A lot of it comes down to presentation and... well, luck.

On the luck note, [@Gimple], I'm soneone (since I've now looked at your thread) that normally WOULD take a bite. However, I JUST agreed to do a couple more RPs since my semester is ending in a week. I don't feel safe adding another to my plate without being sure I can keep a good pace in the roleplays I've agreed to. So, that means that while your RP would normally get my attention, it presently just isn't. I'm busy, and that's the rub of things.

Presentation can also be hit and miss depending on what you're presenting. And truth be told, it also helps if you can say "My roleplay was inspired by <X>," since that gives people something to compare your setup to. For instance... I don't think I'd have gotten nearly the attention I have in Masters of the Hidden Valley if I didn't leave a lot of King of Dragon Pass elements in my interest check.