I've been running a powerful SU profile for the past few weeks, just broke 11k favorites and have just over 100 followers as of right now. My profile has just been growing and gaining in popularity over time and I have been getting a lot of good responses from submitting articles and sharing with my followers.
I also run a few other social media profiles on the web and can promote to those as well, but SU (and even Digg) are my top sellers. If you'd like to discuss pricing and all just PM me or shoot me an e-mail which you can grab off my personal site (jake rocheleau)
Thanks for your time, happy marketing