I see a lot of friend-endorsed adverts which they might not find appropriate (Friend A likes Hooters! etc.). I'm surprised the settlement doesn't allow for a way to show (and reject) which brands you follow might use your name. The adverts people might get featuring you are pretty much a mystery.
Original image plus two (or more) scaled thumbnails. Also, I don't think they're doing any reuse (upload the same pin for 2 different S3 objects of the same image). 5.3Mb / object is still really high though.
I'm really struggling to find a cheap solution to this. So many metrics services seem to be based around conversion to a sale. For ad-supported sites, you need pretty huge numbers to turn revenue, and then you're priced straight out of these kind of products.