Worked example: Time Decay

One visitor, six visits over twelve days and two conversions. How much of each conversion does each channel earn?

Date	Channel (visit)	Action
5/1	Meta Ads
5/4	Google Ads
5/5	Direct
5/7	Meta Ads
5/9	Direct	Conversion $10
5/11	Google Ads
5/12		Conversion $5

This example assumes the view includes all traffic, so direct visits take credit, and that every visit and conversion falls inside the selected date range. The rules themselves are on Attribution models.

Time Decay Attribution 5/1 - 5/12

First we will look at the results of the model and then we will explain the math below:

Source	Visits	Conversions	Conversion Revenue
Meta Ads	2	.625	$4.91
Google Ads	2	.554	$3.63
Direct	2	.821	$6.46
Total		2	$15

Below is the calculation for the 1st conversion for the date range:

Source	Days from Conversion	First Conversion	Pro Rata Conversion	Revenue
Meta Ads	8	2^(-8/7) = .45	.45 / 3.56 = .127	.127 * $10 = $1.27
Google Ads	5	2^(-5/7) = .61	.61 / 3.56 = .171	.171 * $10 = $1.71
Direct	4	2^(-4/7) = .67	.67 / 3.56 = .189	.189 * $10 = $1.89
Meta Ads	2	2^(-2/7) = .82	.82 / 3.56 = .231	.231 * $10 = $2.31
Direct	0	2^(-0/7) = 1	1 / 3.56 = .281	.281 * $10 = $2.81
		3.56	1	$10

Below is the calculation for the 2nd conversion for the date range:

Source	Days from Conversion	First Conversion	Pro Rata Conversion	Revenue
Meta Ads	11	2^(-11/7) = .34	.34 / 3.55 = .095	.095 * $5 = $.47
Google Ads	8	2^(-8/7) = .45	.45 / 3.55 = .128	.128 * $5 = $.64
Direct	7	2^(-7/7) = .50	.50 / 3.55 = .141	.141 * $5 = $.70
Meta Ads	5	2^(-5/7) = .61	.61 / 3.55 = .172	.172 * $5 = $.86
Direct	3	2^(-3/7) = .74	.74 / 3.55 = .209	.209 * $5 = $1.05
Google Ads	1	2^(-1/7) = .91	.91 / 3.55 = .255	.256 * $5 = $1.28
Total		3.55	2	$5