Disclaimer: I work for Ghostery. I respond to protect my own name, not my employer.

Ghostery is not selling user data.

Let me point out a few facts:

All browser-side code is open source https://github.com/ghostery/ghostery-extension and https://github.com/ghostery/ghostery-dnr-extension.

Yes, Ghostery has a subscription based business model and that another reason to great care in protecting users privacy. Take a look on how we use blind tokens to authenticate subscribed users while searching on glowstery.com https://github.com/ghostery/ghostery-search-extension (notice that even when you are a subscribed user there is no session cookie so queries cannot be linked).

Hope this sheds some light on the accusation. If that’s not enough, I do sincerely recommend uBlock Origin or AdGuard on Apple’s platform.