Disclosure: I work for Evidon.
Evidon provides reports to different types of companies that give them information about what trackers appear where, how prevalent they are and/or whether they're in compliance with privacy laws. High-level reports, not "your data."
pokoleo forgot to mention that 1. GhostRank, the feedback feature of Ghostery, is very explicitly opt-in: no data is collected unless you enable it, and 2. We anonymize all of the data that's collected. We have no interest in tracking individual GhostRank users. What's interesting to us is being able to say "This tracker appears on the most websites, or causes the biggest slow-down of a page load on average."
More details here: