Really interesting results of a study on cookie retention have been published in one of the Sun Microsystems blogs yesterday. In his “Web Analytics Analyzed” blog Paul Strupp has revealed the following chart which demonstrates “what percent of users returning after X days on the same computer still have the same cookie”:
The key numbers/findings of this study reveal:
- “Very sharp drop” (to 72%) just 7 days after the initial visit
- 50% of cookies deleted by day 45
- 360 days past the initial visit the rate “levels out at around 20%”
The above data shows that the majority of Internet users who delete cookies do so within the first 30 days. Starting from day 60 the rate of decay acquires a more gradual character, dropping 45% to 40% between days 60 and 120, then from 40% to 30% from day 120 to 210, and from 30% to about 20% between days 210 and 360.
This study has immediate implications for the context of affiliate marketing. It helps merchants answer the question of a fair cookie life to set; and it also makes affiliates better equipped for determining which merchants to partner with based on the cookie life they offer through their affiliate programs.