I have been selling on Redbubble for about a year. I came in here researching print sites as starting to get more requests for prints on my wildlife.  Debating if Redbubble and FAA are the best sites to send them to or is it time to do something like smugmug....
I do get sales through redbubble though....I enable any of the choices the photo works for.  I sell a few prints per month, stickers and pillows.  Before Christmas sold coffee cups and pillows.  I know this is a bit old, but one of the areas I have a tiny bit of experience in and didn't see any responses.