Throughout this report, we refer to cookie stuffing 2.0 as an action by an affiliate whereby the affiliate inserts their tracking code into a link in an attempt to get affiliate sale credit although the user would likely have converted anyway (without any payment to an affiliate). We typically consider a cookie to have been “stuffed” when the end user “appears” to have visited the client site from the cookie stuffer and another marketing channel in a window of five seconds or less (having studied over 50 different cookie stuffers, we see that 98.7% of cookie stuffing happens in five seconds or less); however, in the interest of added conservatism for this analysis, we used a maximum window of two seconds (it is virtually impossible to visit a site from two different sources in two seconds or less).
Where does the “2.0” come in? A new breed of affiliates is sharing affiliate commissions with end users via rebates, social gaming credits or donations to causes. Cookie Stuffing 1.0 relied on ignorance of users to get the cookie stuffed. In Cookie Stuffing 2.0, end users are given an incentive to download browser toolbars and plugins, which allow the affiliate to stuff a cookie when the user visits sites that participate in affiliate programs. Based on our analysis, we present below what we have found to be the Top Ten Cookie Stuffers. At least eight of the ten of the Cookie stuffers incentivize the end user to install plugins/toolbars. To our knowledge, Cltrda.com is the only top Top Ten Cookie Stuffer that provides no apparent benefit to the end user and may be relying on lack of user knowledge.