Time Decay Attribution

What Time Decay Attribution Is

Time decay attribution is defined as a multi-touch model that distributes credit based on recency, assigning more weight to touchpoints that occurred closer to the conversion event under the assumption that recent interactions had more influence on the buying decision. It is a step up in sophistication from linear attribution because it introduces a weighting logic rather than treating all touchpoints equally. According to Analytic Partners (2024), time-decay models correlate 18% better with actual channel impact than linear models for B2B sales cycles under 90 days.

The model reflects a common-sense intuition: the product demo last week probably influenced the buying decision more than the blog post read three months ago.

How is time decay attribution calculated?

Time decay uses an exponential decay function. The most common implementation uses a half-life period (often 7 days):

Credit = Base Credit x (0.5 ^ (Days Before Conversion / Half-Life))

Example with a 7-day half-life and $100K deal:

Touchpoint	Days Before Close	Decay Factor	Credit
Blog post read	42 days	0.016	$1,050
Webinar attended	28 days	0.063	$4,130
Case study download	14 days	0.25	$16,400
Demo attended	7 days	0.5	$32,800
Pricing page visit	1 day	0.91	$45,620

The demo and pricing page visit receive 78% of total credit. The blog post and webinar, which may have been essential for creating initial awareness, receive 5% combined.

Why time decay attribution matters for revenue teams

Time decay attribution is valuable when you need to understand what converts, not just what creates awareness. For revenue teams focused on near-term pipeline optimization, knowing which late-stage touchpoints accelerate deals is more immediately actionable than knowing which early-stage touchpoints create initial interest.

The model is particularly useful for optimizing the bottom half of the funnel: retargeting campaigns, product demos, case studies, and sales enablement content. If your sales cycle length is 30-60 days and you need to increase conversion rates this quarter, time decay shows you where to focus.

How to use time decay attribution effectively

- Pair time decay with first-touch attribution. Time decay excels at showing what converts. First-touch excels at showing what creates awareness. Running both models simultaneously gives you a complete picture of the funnel. - Adjust the half-life to match your sales cycle. A 7-day half-life is standard but may not fit your business. If your average sales cycle is 120 days, a 14 or 21-day half-life better captures the influence of mid-funnel touchpoints. - Use time decay for campaign optimization, not strategic budgeting. Time decay tells you which campaigns accelerate conversion. It does not tell you which channels are essential for creating the initial audience. Use it for tactical optimization while relying on marketing mix modeling for strategic allocation. - Compare time decay results to linear results. Where the two models agree, you have high-confidence insights. Where they differ significantly, you have identified channels whose timing in the journey (early vs. late) matters more than their presence alone.

Common mistakes with time decay attribution

Cutting top-of-funnel programs based on time decay data. Time decay systematically undervalues awareness and brand-building activities because they happen early in the journey. If you cut SEO or content programs because time decay says they contribute little, you will eventually see a decline in total pipeline as the top of the funnel dries up. Using a universal half-life across all segments. Enterprise deals with 6-month cycles and SMB deals with 30-day cycles should not use the same decay rate. A 7-day half-life in a 180-day enterprise cycle would attribute essentially zero credit to everything before the last month.