SlickDeals, as with most deal sites, is the equivalent of a B movie in Hollywood. They're considered trashy, low quality sites. Buying SlickDeals is close to bottom fishing if you're Amazon.

Goodreads was classy by comparison and was/is not primarily about deals or referral links. Amazon considers itself to own the book category, period. Books will always hold a special place in their heart as the origination of the company. Amazon, as with all big companies, also considers its brand when it purchases other things. (some of the tech echo chamber may laugh at that notion, however that's nothing more than ignorance as Amazon has an extraordinary brand among the general population)