What Features Would You Want in a Sponsored Post Market Place

I know lots of you out there are either bloggers or SEO’s/webmasters. And many of you are both. As you may know by now, I love the paid-post model for link development and targetted advertising,s o I’d really love some feedback about what features you think would be super-cool in a payperpost-type sponsored posts marketplace.
Drop ’em in the comments, thanks.