I voted, but maybe I shouldn't, because I am not in all those sites.
I have invested some time in Zazzle and today, even after months without creating anything, I'm selling more there than in any of the micros. It takes me some time to create a new product, but then for the new ones with a different image the process gets much easier, as I can just replace the image, change texts (if any) accordingly and then title/description/keywords, using copy&paste.
Besides Zazzle, I have a few images in FAA and Imagekind, never sold anything.
In the latter I only use landscapes, nature and architectural images; in Zazzle I use also some of what I have in microstock (especially for business cards), including illustrations.