Linear Attribution Model for SaaS: Fairness vs Dilution

Linear attribution splits a sale evenly across every touch — so a $500 sale spread over four channels credits each one exactly $125, no matter which did the real persuading.

Linear attribution is the multi-touch model that divides a conversion’s credit equally among all the touchpoints in the buyer’s journey. It is the simplest way to stop pretending a single click did all the work, and for that reason it is the natural first step up from first- and last-touch: 22% of TrackRev workspaces run it as their model (TrackRev platform data, Q2 2026), second only to last-touch.

Its great virtue is fairness — every contributing channel shows up in the report.

Its great flaw is that fairness and accuracy are not the same thing: treating a throwaway banner and a 30-minute demo as equal contributors dilutes the decisive touches.

This guide works the maths, names the trade-off precisely, and says who linear actually suits — always with the same goal in view: ranking channels by the revenue they book, not the clicks they send.

Why this matters for your revenue

Single-touch models make a channel’s value binary: it either got the credited click or it did not. That is fine for finding one or two channels that work and hopeless for a funnel where several channels genuinely contribute.

Linear is the first model that lets all of them show up, which changes budget decisions because a channel that never gets the first or last click — mid-funnel nurture, consideration content, a comparison-stage affiliate — finally appears with a number instead of a zero.

That visibility has direct financial consequences. Under last-touch, an assisting channel shows near-zero revenue and becomes a cut candidate; under linear, the same channel shows its share and can be defended and grown.

The risk runs the other way too: because linear weights every touch equally, it flatters low-effort channels — a single display impression collects the same $125 as a deep product demo — so a team that treats linear as gospel can over-invest in cheap, high-frequency touches that merely brushed the journey.

The honest use of linear is as one view among several, read for its strength (nobody is zeroed out) while staying alert to its weakness (nobody is prioritised).

For where these channels land over their lifetime, compare channel LTV per source.

What linear attribution is

Linear attribution gives every touchpoint in the buyer’s journey an equal share of the conversion’s credit and revenue — if there are four touches, each receives 25%. No touch is privileged for being first, last, or in the middle; the model’s entire premise is that, absent better information, treating every recorded interaction as an equal contributor is more honest than crowning one.

That premise is a deliberate refusal to guess. First- and last-touch make a strong claim about which touch mattered; linear declines to, spreading credit uniformly rather than risk being confidently wrong about a single winner.

Whether that is wisdom or evasion depends on your funnel — which is the trade-off the rest of this guide unpacks.

A worked example: a $500 sale

The same $500 annual-plan journey used across this series: four touches over 28 days. Under linear the arithmetic is the easiest of any multi-touch model.

The four-touch journey

Organic search on day 1, newsletter on day 9, an affiliate link on day 21, and a paid-search click on day 28 — four touches, all inside a 30-day window, all treated as equal contributors by linear.

How linear credits the $500

Divide the sale by the number of touches: $500 across four touches is $125 each. Organic search, newsletter, affiliate, and paid search are each credited exactly $125 — a quarter of the sale apiece.

The discovery touch and the closing touch are treated identically, as are the two in between.

The maths, step by step

Count the qualifying touches inside the attribution window (four), then assign each an equal share of the revenue: $500 ÷ 4 = $125. If a journey had three touches inside the window, each would take $500 ÷ 3 = $166.67; with five, $100 each.

The only variable is the touch count, which is why linear’s output shifts as journeys lengthen — every extra touch makes each slice thinner.

The same sale under all five models

Linear’s flat $125-across-the-board sits visibly between the single-touch extremes and the recency-weighted models. It is the only row where every channel is identical.

Reading the comparison

Compare the linear column with position-based: both credit all four touches, but position-based pushes $200 each to the first and last and only $50 to the middle two, while linear insists on $125 everywhere.

If you believe discovery and conversion genuinely matter more than the touches between them, position-based’s emphasis is closer to reality; if you believe every touch is roughly comparable, linear’s evenness is more honest.

The right choice is a claim about your funnel, not a mathematical fact.

The strengths and the blind spots

Linear’s single design decision — equal weighting — is simultaneously its best and worst feature.

The case for linear: fairness

Linear earns its place when journeys are genuinely multi-channel and you need every contributing channel to appear in the report.

For a B2B SaaS buyer who discovers you on YouTube, subscribes to the newsletter, attends a webinar, and converts through an affiliate, linear is the only single model of the three TrackRev ships that credits all four — and that visibility is what lets you defend content and awareness spend in a budget meeting.

It is also the safest view when you are not yet sure which touches matter most, because it refuses to over-commit to any one, so it will not confidently mislead you the way a single-touch model can.

The case against linear: dilution

Linear’s fairness is also its flaw: it assumes every touchpoint contributed equally, which is rarely true. A throwaway banner impression and a 30-minute product demo each collect the same slice, so trivial touches get inflated and decisive ones get diluted.

The more touches a journey has, the thinner and less meaningful each slice becomes, and the easier it is for a high-frequency, low-value channel to accumulate credit simply by appearing often.

If you find linear flattering low-effort channels, that is the dilution problem, and it is the reason position-based and time-decay exist.

Who should use linear

Linear is a strong middle option — more honest than single-touch for multi-channel funnels, simpler and more defensible than weighted models. Match it to your situation.

A good fit for multi-channel SaaS funnels

Reach for linear when several channels genuinely contribute to your typical sale and you need all of them visible — the classic case being a growth-stage SaaS running newsletter, affiliates, content, and paid in parallel.

It is also the right choice for the all-hands revenue report, where the goal is to credit every team’s channel fairly rather than to crown a winner.

For long, many-touch B2B journeys, linear is often the most defensible single view; see attribution for long B2B cycles.

A poor fit when touch quality varies wildly

Avoid leaning on linear when your touches differ enormously in effort and influence — some journeys are a stray impression plus a serious demo, and equal weighting misrepresents both.

Avoid it too for simple single-channel purchases, where there is nothing to spread and linear collapses to last-touch anyway.

When touch quality varies, a weighted model like position-based better matches reality, even though TrackRev does not ship it as a preset — more on that below and in the models compared.

Linear and TrackRev

Linear is the third model TrackRev ships, alongside first-touch and last-touch, computed from the same stored click log.

How to run linear in TrackRev

Switching your dashboard to linear is a dropdown — the same raw click journeys that feed last-touch are re-apportioned equally with no re-tagging.

That makes linear ideal as the “fair” cross-check you consult alongside your default: flip to it to see which assisting channels last-touch was hiding, then decide. See multi-touch attribution for SaaS for how the shared log makes this instant.

Linear as the honest all-hands view

Because linear credits every channel, it is the least contentious number to put in front of a whole team: no channel owner feels zeroed out, and cross-team accountability stays honest.

Many TrackRev teams keep last-touch for paid-spend calls and use linear for the shared revenue report — two views of one click log, each for the decision it suits.

Why TrackRev stops at three models

TrackRev ships first-touch, last-touch, and linear deliberately, not as a limitation.

These three are fully auditable — you can trace exactly why a channel got the credit it did — and they behave sensibly at SaaS conversion volumes, where fancier weighted or algorithmic models mostly add noise and opacity.

Linear is the multi-touch workhorse in that set: it captures the “everyone contributed” insight without introducing tuning parameters you cannot explain to finance.

When NOT to use TrackRev

If your billing is not on Stripe, Paddle, Polar, or Lemon Squeezy, the revenue join does not apply.

If you specifically need a weighted preset like position-based or time-decay, or a black-box data-driven model, TrackRev deliberately does not ship those — it stands behind three auditable models instead, for explainability and small-data reliability.

And if you sell physical products or run a CRM-led enterprise motion, a specialist tool fits better. TrackRev is for SaaS teams that want revenue tied to channels across models they can defend line by line.

The stack maths is the consolidation case: Bitly Growth (~$35/mo) plus Rewardful Starter (~$49/mo) is $84+/month for two tools with two definitions of a sale, while TrackRev is $39/mo for all three products on one.