Almost every company with a half decent optimization strategy will use similar sites to measure interactions and categorize users. Most of these measurements a

Almost every company with a half decent optimization strategy will use similar sites to measure interactions and categorize users. Most of these measurements are things that a site could do on its own (like analyzing how effective a call to action is) but it makes sense time and cost wise to outsource to an expert. If you're worried about this- use an adblocker or don't go to corporate sites.