I am only accepting artfolios, graphics sites, or sites with something to offer artists such as brushes, stock images etc.
I periodically clean up my affiliates. I remove people for the following.
Don't have a link here on their affiliates page
Site has not been updated or is on hiatus for more than a year (exceptions made for friends/special circumstances)
Site is open but most sections don't work
They've been caught copying other's work/layouts/art
Site contains malicious script virus that could harm someone's computer
I won't warn everyone before removing them because it's very time consuming. If you were removed for one of these reasons and would like to re-affiliate, tag me and let me know. Last affiliate cleanup: March 11th, 2011 - Removed 12 My Online Family