Hi, I work on the Ghostery extension.
Ghostery used to belong to a company named Evidon, which had this business model of collecting data to sell it in some form (the feature was called "Ghostrank"). In 2017, Ghostery was acquired by Cliqz (which builds an independent and private search engine from Germany), and since then a few things happened: (1) the extension was open-sourced, (2) Ghostrank was completely removed and (3) Ghostery is now developing paid products as a business model. For example we launched Ghostery Insights[1] and Ghostery Midnight[2] recently, both of which are subscription-based.
[1]: https://www.ghostery.com/insights/ [2]: https://www.ghostery.com/midnight/