Read Downing My Public Domain Stance with a Swig of Castor Oil (CogDogBlog)
Beyond movies and perhaps MAD magazine references I have no direct experience with being forced castor oil as a cold remedy. But there is an old advertisement in an image that is in the public doma…
This also reminds me a bit of the small print in newspaper circulars for stores like Macy’s announcing huge 40% off sales where they indicate that the original list prices of the items is not an indication that they ever sold for that price. Which means their advertisements are really just stating the starting price and make it seem like there’s a big discount applied.

By analogy, I have to wonder if the listings on Almay actually result in any significant sales? I suspect that the uploader probably spent more time handling upload, curation, and management than they’d likely ever earn back unless they were doing it at scale? 

Perhaps it may be worth it for a professional photographer to supplement their income, or it may affect someone with hundreds of thousands of photos, but I’d have to agree with Alan’s take that I’d rather have the credit and the kind emails too.