Cathy, I've been checking out your blog on occasion, I even commented on one of your blog posts. I have seen you posting here in the forum for a while now, I have a suggestion that may help with your blog.
Right now you are using a broadcast approach posting to those who are reading the forum, asking them to "Come join me!". Perhaps as a way of gathering even more participants, you could do something a bit more personal and go artist direct, or direct marketing. Most people want to be acknowledged for what they do or have done, what they have created, and not many will take the appropriate time to market themselves. Also, the number of users on the forum is very small relative to the number of registered members of FAA.
A way of increasing you responses might be to put together an introduction letter, similar to the one you present here on the forum, and contact artists directly through personal messages. Send a intro letter with your pitch that you have looked at their portfolio, and would like to feature them on your art blog. It creates a whole new dynamic, and could possibly work for you. It would be almost the same exact pitch, but more direct. If you take the time to approach people one on one, and you acknowledge their specific artworks, you may be able to increase your participation rate just a little bit.
I know for me, that when people take the time to PM me, I give much more weight to what they have to say.
-YoPedro