The marketing funnel splits the path from first exposure to purchase into three stages: top of funnel (TOFU, awareness), middle of funnel (MOFU, consideration) and bottom of funnel (BOFU, purchase). Its value is not the diagram but the fact that it lets you measure each stage by its own metric. The most common mistake is judging an awareness campaign by sales metrics and switching it off, when that campaign was producing not sales but the audience you could sell to.
What does each stage do?
Every stage has a different job, goal and correct metric. Applying the same ad, message and expectation across all three makes the whole funnel inefficient.
- Top of funnel: reaches people who do not know you. The goal is interest and audience, not conversion. Metrics: reach, video views, qualified visits.
- Middle of funnel: persuades people who are interested but undecided. The goal is staying in the comparison set. Metrics: returning visitors, page depth, email signup.
- Bottom of funnel: closes people at the decision point. The goal is conversion. Metrics: conversion rate, acquisition cost, revenue.
- Post-funnel: retains customers who bought. Most businesses skip this, and it is often the highest-return stage.
Why can't every stage share one metric?
A top-of-funnel campaign naturally shows a low conversion rate, because most of the people it reaches are not in buying mode yet. Judging that campaign by ROAS is like measuring sowing with a harvest metric. The right approach gives each stage its own goal and tracks the stage-to-stage pass rate: if more people move from top to middle, the campaign is doing its job.
How do you split budget across stages?
There is no universal ratio, but a workable start in a mature account is roughly 30% top, 25% middle and 45% bottom. Low brand awareness pushes the top share up; strong existing demand pushes the bottom up. One rule matters: taking the bottom share to 100% raises ROAS in the short term and collapses volume a few months later.
Where in the funnel are you stuck?
Ads Sensor unifies campaigns across four platforms and shows which stage actually produces profit through AI analysis.
Why is the middle the weakest link?
Most businesses advertise at the top, remarket at the bottom and do nothing in between. Yet most of the buying decision happens in the middle: people compare, ask about price, read reviews, look at competitors. Different things work here: comparison content, frequently asked questions, customer reviews, clear delivery and return terms. The advertising equivalent is a specific message for people who saw the product page but did not add to cart.
- Define the stages: write down which behavior represents which stage.
- Give each stage its metric: reach and pass rate at the top, conversion and cost at the bottom.
- Track pass rates: the drop between stages tells you more than individual campaign performance.
- Fill the middle: feed undecided people with comparison and trust content.
Which channel fits which stage?
Channel choice follows the stage. Visual discovery platforms are strong at the top; search ads belong at the bottom, because that is where intent lives. Remarketing connects the middle to the bottom. We detailed that split in Google Ads versus Meta Ads; for remarketing structure see our remarketing strategy guide.
The funnel keeps you from squeezing every campaign into one table and lets you ask each the right question. To watch stage-to-stage movement in one dashboard, join the Ads Sensor beta.