Do you need an account to actually make Pinterest useful?
Sometimes I do a Google Image search because I found something interesting, but don't know what it is, so I'm hoping of going to a page that describes what I was looking at. Pinterest shows up as a result, but with no backstory nor does it lead me back to a source, so it's worthless as a search result. It'd the ExpertsExchange of image searches.
Endy's advice of using `-inurl:pinterest` seems invaluable and I'll be adding that for all image searches in the future.