Welcome to the Q&A Forum

So, digging deeper into this issue, it turns out that we can't rely on status code as a reliable indicator of page validity for affiliate network URLs. Most of them turn up with a 200. Looking at possible custom solutions from affiliate compliance monitoring services now. No one seems to be doing this thing that I need to do, but it sounds like a great business idea for someone with coding experience and more entrepreneurial spirit than I've got. Just gonna throw that out there.

Thought provoking discussion Rebecca! I'm with you in thinking there is potential for Google to start using misleadingly labeled images in it's ranking algorithm. Alt tags in particular. They're supposed to be used, in part, to help visually impaired search engines and people understand what's being shown on the page. If they don't do that, if they're just stuffed with keywords, they lessen the value of the page. In that context "Hawaiian sunset" has more value that "church", "travel site" or "inspirational quote", even if dozens or hundreds or thousands of other sites use the same descriptor. I also agree with Egol's opinion that unique content derives value from its perceived popularity; its ability to earn repeat and lengthy visits as well as exposure, links, and shares. I consider it a best practice to use unique images accurately named and described (using alt tags) with a brief and accurate description of the image that incorporates keywords. Not easy or even possible all of the time, but a good target to aim for.