Thought I'd point out something regarding this. I think one of the biggest factors in whether your request is picked up quickly is in the simplicity of your request (though not necessarily; I have no idea what yours looked like). When I'm looking for a sig or wallpaper to take on, I look for things where someone links their toon, states their gear, and nothing else. No posing, no additional toons, no color schemes (especially if the color scheme doesn't compliment the gear choice, ugh), and no weapons that clash with the gear set. I like to have creative freedom over what I'm doing.
I can't speak for the rest of the artists, of course, and I see them doing things like grabbing multiple toon wallpapers and such, so I'm sure they're not the same as me; however, it's something to think about. I almost passed over the last request I took because he requested the druid standing (which I ignored in the end ;x ) and asked for a pet that didn't match his toon aesthetically. I'm a picky bastard.
Edit: Thought I'd add that there's nothing inherently wrong with multiple toon requests. I specifically won't take them because I spend SO much time fiddling with the lighting on a single toon that taking on 2-3 would make my brain explode.
You'd enjoy my request, then