Google was the most prevalent employer of trackers, according to Cliqz and Ghostery. Trackers related to its Google Analytics service appeared on 46.4% of webpages examined. But trackers related to its other services, such as DoubleClick and AdSense, were also comparatively prevalent.
Facebook was the other big tracking enterprise, with its Facebook Connect service found on more than one-fifth (21.9%) of pages.
So why should publishers and advertisers care if users are drowning in a deluge of trackers? For one, tracking technologies allow for both segment targeting and retargeting. But the overuse of such marketing techniques has the potential to backfire on advertisers if audiences end a browsing session with concerns that companies are gathering too much data on them.
In some cases, high ad frequency rates can result in the installation of ad blockers, which are gaining steam in the US. eMarketer estimates that a little more than 30% of US internet users will use an ad blocker in 2018, up from 15.7% in 2014.