Most B2B teams still talk about the customer journey using a model that was built for a different era. The traditional sales funnel (awareness → consideration → conversion) treats the buying process as linear, ends at the moment of purchase, and assumes the marketing job is done once the deal closes. That model worked reasonably well in a transactional, single-purchase world. It fits much less well in modern B2B, where most revenue growth comes from existing customers rather than new logos, where buying journeys loop and skip stages rather than progressing neatly, and where the customers who buy today drive the awareness that brings tomorrow's buyers in.

Two alternative models have emerged to address these gaps. The hourglass funnel extends the traditional funnel beyond purchase, adding stages for retention, expansion, and advocacy. The flywheel (popularised by HubSpot) replaces the funnel altogether with a circular model where customer momentum powers ongoing acquisition. Both improve on the linear funnel; both make different assumptions about how customer momentum produces growth.

This guide compares the three models, explains when each fits, and then goes deep on the hourglass funnel. The hourglass is the right model for most growth-stage and mature B2B SaaS, because the expansion-and-advocacy economics it captures match the actual mechanics of how modern B2B revenue is produced. The guide is aimed at B2B founders, marketing leaders, and growth operators thinking about how to model their customer journey and align the team around it.

The three models compared

The three customer journey models in common use today represent three different assumptions about how revenue is produced.

The traditional funnel assumes the buying journey is linear (awareness, consideration, evaluation, conversion) and ends at the point of purchase. The marketing function's job is to fill the top, the sales function's job is to convert the bottom, and once the deal closes the relationship moves to a separate (often less-resourced) part of the organisation. The funnel optimises for new-logo acquisition: pipeline volume, conversion rates, sales cycle length, win rate.

The traditional funnel still fits some businesses well. Single-transaction sales (most B2C, some transactional B2B), short sales cycles, low expansion potential, businesses where the customer relationship genuinely ends at the purchase. For those segments, the funnel is the right conceptual model and the right operating system.

For most modern B2B, particularly B2B SaaS and B2B services with recurring relationships, the funnel underrepresents where the actual revenue comes from. Expansion revenue, retention, and advocacy-driven new pipeline are often the largest sources of net new revenue, and a funnel that ends at purchase makes them invisible to the model.

The hourglass funnel keeps the structure of the traditional funnel for the pre-purchase stages but adds a second half that widens again after conversion. The post-purchase half includes onboarding, adoption, retention, expansion, and advocacy. The visual metaphor: the funnel narrows as buyers self-select through pre-purchase stages, then widens again as customers expand their use, deepen their engagement, and become advocates who bring new buyers in.

The hourglass fits most modern B2B SaaS and B2B services with recurring relationships. It captures the post-purchase value (expansion, retention, advocacy) that the traditional funnel ignores. It maps cleanly to operational disciplines that have emerged over the last decade (customer success, customer marketing, expansion sales motions). For most growth-stage and mature B2B businesses, the hourglass is the better conceptual model than the linear funnel.

The flywheel replaces the funnel entirely with a circular model where customers are at the centre and the momentum of customer satisfaction powers ongoing growth. HubSpot's version frames it as three coordinated motions (attract, engage, delight) that all contribute to and benefit from the customer at the centre. The flywheel emphasises the compounding effect of happy customers driving new acquisition through word-of-mouth, advocacy, and reduced friction across the lifecycle.

The flywheel fits businesses where customer-driven growth is the dominant acquisition motion: PLG-led B2B SaaS, brand-led businesses with strong community dynamics, businesses where viral or word-of-mouth growth is the primary engine. For these segments, the circular model captures the dynamics better than either the funnel or the hourglass.

In practice, many modern B2B teams use elements of both the hourglass and the flywheel. The hourglass provides the operational structure (clear stages, measurable transitions); the flywheel provides the conceptual reminder that customer momentum compounds and feeds the top of the funnel. The two are complementary more than competing for most teams.

When each model fits

The choice between models depends primarily on the business mechanics and stage.

The traditional funnel is the right model when the customer relationship is genuinely transactional (single purchase, short cycle, no meaningful post-purchase expansion or advocacy potential). Some B2B segments still operate this way; many do not.

The hourglass is the right model when the customer relationship is recurring or extends meaningfully past the first purchase, when expansion revenue is a real growth lever, and when the team has the operational capacity to invest in post-purchase disciplines (customer success, customer marketing). This describes most modern B2B SaaS, most B2B services with retainer relationships, and most B2B businesses with consumable or repeat-purchase products.

The flywheel is the right model when customer-driven momentum is the dominant acquisition engine: PLG-led B2B SaaS where users invite other users into the product, brand-led businesses with strong community dynamics, businesses where word-of-mouth and advocacy produce more pipeline than direct outbound or paid acquisition.

A useful rule for most modern B2B businesses: start with the hourglass as the operational model (because it maps cleanly to disciplines and metrics), and use the flywheel as the conceptual reminder that the bottom of the hourglass feeds the top. The two together cover most of the dynamics that matter.

The hourglass funnel in depth

The hourglass funnel has eight to ten stages depending on how granular the model is drawn. The standard structure splits into pre-purchase (the upper funnel) and post-purchase (the lower funnel widening back out).

Awareness. The customer first learns about the brand, the category, or the problem the brand solves. In modern B2B, awareness is largely channel-dispersed and partly invisible: peer recommendations in Slack groups, podcasts, ungated content, LinkedIn presence, communities, conference exposure. The dark-funnel reality is that much of the awareness happens on surfaces marketing automation cannot track. The implication for the model: the awareness stage is real and matters enormously, but should not be evaluated only through trackable channels.

Engagement. The buyer interacts with the brand in some meaningful way: reads multiple pieces of content, follows the brand on LinkedIn, listens to the podcast, attends a webinar, joins a community. Engagement is a softer signal than the historical "MQL" but a more honest one. Modern marketing teams tend to track engagement at the account level (signals from across the buying committee) rather than at the individual level.

Consideration and evaluation. The buyer is actively researching solutions in the category and comparing options. This is where the buying committee is forming, where review platforms (G2, Capterra) and analyst content matter, where comparison content drives pipeline, and where references and case studies become decision-relevant. The discipline at this stage is making the brand discoverable and credible at the moments the buyer is comparing.

Conversion (purchase). The deal closes. The buyer becomes a customer. In B2B SaaS, this is typically a contract signing or a self-serve sign-up at the relevant tier. In B2B services, it is a signed agreement.

Onboarding and adoption. The first 30-90 days of the customer relationship determine the long-term loyalty outcome more than any other period. A customer who reaches their first meaningful value moment quickly is far more likely to renew, expand, and advocate. A customer who struggles through onboarding is far more likely to churn within the first year. The discipline at this stage is structured: defined milestones, clear success metrics, dedicated onboarding resource, regular check-ins.

Retention. The customer continues to use and pay for the product or service. The discipline is operationally executed through customer success: health scores that surface at-risk accounts before they churn, regular business reviews, proactive value delivery, customer education programmes. The metric that matters at this stage is Gross Revenue Retention (GRR), which strips expansion out and shows pure churn dynamics. Strong B2B SaaS sits at 90%+ GRR.

Expansion. The customer grows their relationship with the brand: upgrades to a higher tier, adds seats, adopts additional product modules, or buys complementary offerings. In modern B2B SaaS, expansion is often the largest single source of net new revenue, with significantly better unit economics than new-logo acquisition (the customer is already in the building, the product is already adopted, the trust is already established). The discipline: identify expansion signals through usage data, design the product for expansion paths, run the expansion conversation through customer success rather than separate sales motions in most cases.

Advocacy. The satisfied customer becomes a source of pipeline impact for the brand: provides references for new prospects, agrees to case studies, makes referrals to peers, participates in customer events, contributes to community. Modern customer marketing programmes structure advocacy explicitly rather than relying on it to happen organically. The advocacy stage is where the bottom of the hourglass loops back into the top, feeding new awareness through dark-funnel mechanisms.

The visual metaphor of the hourglass is useful: the funnel narrows as buyers self-select through pre-purchase stages, then widens again as customers expand their use, deepen their engagement, and become advocates who bring new buyers in. The widening of the bottom half captures the compounding economics that the traditional funnel misses.

The operational disciplines that make the hourglass work

The hourglass funnel as a conceptual model only produces results if the team has the operational disciplines to execute each stage. Several modern disciplines map directly to the hourglass.

Customer success owns the post-purchase relationship. The CSM (customer success manager) is responsible for adoption, retention, and expansion across a defined book of accounts. Book sizes vary by segment: enterprise CSMs handle 5-15 strategic accounts, mid-market CSMs handle 30-50, SMB CSMs handle 200-500 with mostly automated touches. Modern customer success teams use dedicated tooling (Gainsight, Catalyst, ChurnZero, Vitally, Planhat) to operationalise health scoring, business review workflows, and account intelligence.

Customer marketing owns the advocacy and customer-as-pipeline play. The function structures references, case studies, customer events, customer-facing content, referral programmes, and community engagement into a coordinated motion that turns loyal customers into pipeline impact. Customer marketing has split off from broader B2B marketing in most growth-stage B2B SaaS, with dedicated team members focused on the customer base rather than on net-new acquisition.

The expansion sales motion structures the upsell, cross-sell, and seat-growth conversations. In some organisations, expansion is owned by the customer success function (the CSM has the relationship and runs the conversation). In others, dedicated expansion AEs work alongside CSMs on larger expansion opportunities. Either model can work; the integration between the two roles matters more than the choice.

The community function (in companies that have one) sustains the customer community: Slack or Discord groups, user conferences, customer advisory boards, partner programmes. Community is one of the highest-leverage advocacy channels available for mid-market and mature B2B brands.

Customer success tooling (Gainsight, Catalyst, ChurnZero, Vitally, Planhat) provides the operational infrastructure for the post-purchase half of the hourglass. The tools centralise account data, automate health scoring, manage QBR workflows, and surface signals that would otherwise stay scattered across CRM, support, product analytics, and email. For most growth-stage B2B SaaS, dedicated customer success tooling pays back quickly.

The operational discipline that ties the hourglass together is the integration between the pre-purchase and post-purchase halves. The marketing and sales teams that own the upper funnel need to hand off cleanly to the customer success and customer marketing teams that own the lower funnel. The hourglass model only produces results when this handoff is structured rather than ad hoc, and when the customer experience across the boundary feels continuous to the customer rather than disjointed.

Measuring the hourglass

The metrics that matter for the hourglass funnel are different from the metrics that matter for the traditional funnel. The traditional funnel optimises for top-of-funnel volume and conversion rate; the hourglass optimises for the lifecycle.

Pre-purchase metrics still matter. Pipeline created, conversion rates by stage, sales cycle length, win rate, customer acquisition cost (CAC). These tell the team whether the upper funnel is producing.

Post-purchase metrics are where the hourglass adds value. Net Revenue Retention (NRR) is the master metric, combining retention and expansion in a single number that maps directly to growth and valuation. Top-quartile B2B SaaS sits at 110-115% NRR; category leaders sit at 120-130%+. Below 100% means the existing customer base is shrinking each year, regardless of how many new logos the sales team adds.

Gross Revenue Retention (GRR) strips expansion out and shows pure churn dynamics. Strong B2B SaaS sits at 90%+ GRR. The combination of NRR and GRR shows whether retention and expansion are each contributing in the right proportions.

Customer health scores are the leading indicator the dashboard metrics lag. A drop in average health score across the customer base usually predicts a rise in churn six to twelve months later; a rise in average health score usually predicts an increase in expansion. The companies that operationalise health scores intervene before the lagging metrics show the problem.

Advocacy metrics capture the bottom-of-hourglass-feeding-the-top dynamic. Reference activity, case study production, NPS as an advocacy proxy, referral pipeline, community participation, customer-driven content. These are softer than the financial metrics but tell the team whether the advocacy stage is actually producing pipeline impact.

LTV:CAC ratio ties the whole hourglass together. Customer lifetime value (LTV) divided by customer acquisition cost (CAC) shows whether the unit economics are sustainable. The healthy floor is around 3:1; excellent businesses sit at 5:1 or higher. The hourglass model improves LTV (through retention and expansion) and often improves CAC over time (through advocacy-driven acquisition), which compounds the ratio in the right direction.

The strategic dashboard for a hourglass-led B2B business combines NRR (the master metric for the bottom half), pipeline metrics (for the top half), customer health scores (the leading indicator), advocacy metrics (the loop closure), and LTV:CAC (the unit economics). Together these tell a clearer story than any single metric.

Buyer journeys aren't actually linear

Worth saying clearly: the hourglass funnel is a useful conceptual model, not a literal map of buyer behaviour. Real B2B buyer journeys are messy. Buyers loop back to earlier stages, skip stages entirely, return to consideration after evaluation, drop out and come back months later, and rarely move neatly through any funnel from top to bottom.

The dark funnel reality is that most B2B buying happens invisibly. By the time a buyer fills out a form or books a demo, the buying decision is largely made, often based on conversations and content the brand never tracked. Modern marketing teams use self-reported attribution ("how did you hear about us?" on demo request forms) to understand what's actually driving pipeline, because the trackable channels marketing automation gives credit to often aren't the actual source.

The implications for the hourglass model: treat it as a useful framework for organising the team and the metrics, not as a literal description of how buyers move. The stages are real and matter; the linear progression between them is more aspirational than actual. The teams that hold both ideas at once (the model is useful, the reality is messier) tend to operate with appropriate clarity; the teams that treat the funnel as literal truth tend to over-engineer their attribution and miss the dark-funnel mechanics that drive most of the pipeline.

How to choose and operationalise the right model

For most modern B2B businesses, the practical recommendation is to operate on the hourglass model with the flywheel as the conceptual overlay. The hourglass provides the operational structure (clear stages, measurable transitions, defined disciplines for each); the flywheel reminds the team that customer momentum compounds and that the bottom of the hourglass feeds the top.

The traditional funnel is appropriate when the customer relationship is genuinely transactional: single purchase, short cycle, no meaningful post-purchase opportunity. For most B2B SaaS and most B2B services with recurring relationships, the traditional funnel underrepresents the actual revenue mechanics.

The flywheel as the primary model is appropriate when customer-driven momentum is the dominant acquisition engine: PLG-led B2B SaaS, brand-led businesses with strong community dynamics, businesses where viral or word-of-mouth growth is the primary engine. For most other businesses, the flywheel is more useful as a conceptual overlay than as the operational model.

The pragmatic sequence for adopting the hourglass:

First, map the current customer journey through the eight to ten hourglass stages. Identify which stages have defined ownership and which don't. Most B2B teams find that the upper funnel is well-resourced and the lower funnel is under-resourced.

Second, invest in the operational disciplines for the lower funnel: customer success, customer marketing, expansion motion, customer success tooling, community (where appropriate). The investment usually pays back through improved NRR within a few quarters.

Third, integrate the metrics. Move NRR to the centre of the executive dashboard. Add health scores as the leading indicator. Add advocacy metrics to capture the loop closure. Don't drop the traditional funnel metrics, but stop treating them as the whole story.

Fourth, integrate the team. The marketing and sales teams that own the upper funnel need to hand off cleanly to the customer success and customer marketing teams that own the lower funnel. The customer experience across the boundary should feel continuous to the customer, not disjointed.

For B2B teams that want to operationalise the hourglass funnel as part of the wider pipeline strategy (LinkedIn, multi-channel outbound, content, podcast, paid acquisition, customer marketing, advocacy), GROU does this as part of the agency offering. GROU also publishes a free hourglass funnel template on Miroverse and a downloadable hourglass funnel guide for teams that want to map their own customer journey through the model. To talk through the system end to end, book a call.