I like Ghostery better. It breaks less websites for me and provides more data on each particular tracker with a source link and a description for the company behind it. Disconnect just shows a title with a number. It has a nicer and more functional UI. I like a popup on page load where you can instantly see what is blocked and what isn't. There's an option to "run once" a blocked widget on page, which can be handy.
http://www.technologyreview.com/news/516156/a-popular-ad-blo... From the article: A Popular Ad Blocker Also Helps the Ad Industry Millions of people use the tool Ghostery to block online tracking technology—some may not realize that it feeds data to the ad industry. It's good to have alternatives, and I prefer Disconnect as Ghostery's motivations seem a little clouded.
I can't think of a clear business model for disconnect.me.
In any case, it's good to have a choice. People who are serious (who don't mind breaking everything) are probably using something like RequestPolicy to control cross-site requests. https://www.requestpolicy.com/