WebTrends says customers who have switched to first-party cookies have tracked an average 10-15 percent more unique visitors and 13-30 percent more repeat visitors than the numbers seen using third-party cookies in the same period, DM News reports (via MediaBuyerPlanner). Customers who switched also report more than a 300 percent jump in accuracy.

According to WebTrends, a deeper analysis reveals an incremental impact on the number of visitors attributed to campaigns, with some sites tracking 10-30 percent more visitors responding to specific marketing campaigns.