What are some alternatives?
When comparing Crystal and Ghostery, you can also consider the following products
BlockBear - Block ads and protect your privacy on iOS with a bear
Adblock Plus - AdBlock Plus is a browser extension for Firefox, Chrome, Opera, and several other popular browsers that prevents intrusive ads like pop-ups and malicious code from appearing on websites you visit.
StopAd PRO - The ultimate ad blocker for Windows and Mac.
Privacy Badger - Privacy Badger blocks spying ads and invisible trackers. How is Privacy Badger different from Disconnect, Adblock Plus, Ghostery, and other blocking extensions?
Goodly - Student loan repayment as a employer benefit
uBlock Origin - Popular and efficient blocker for Chromium, Chrome, Edge, Firefox, Opera, Safari, Thunderbird.