"Putting Pinterest at the top of image search results is effectively nothing more than a funnel to onboard more users for Pinterest, they rarely, if ever, have any relevance. I can't imagine why Google hasn't knocked them out of the results entirely at this point." Absolutely. Pinterest makes Google Image Search much worse than it otherwise would be. I haven't clicked through to Pinterest from an image search for a while, but IIRC you couldn't click through to the image without getting 1. pestered to login and 2. having to scroll through multiple pages once you logged in. I have a vague recollection of this not being compliant with Google Webmaster Guidelines, but I can't recall which specific section, and it's not as if Pinterest is the only large player allowed to get away with breaches the average webmaster would be deindexed for.