Last month I started a contest to give 2 Rapidshare Premium Accounts. As my blog is new so the contestants were less. If you are planning to start a contest on your blog have a look at this post first.
Here I am giving a list of some websites that can provide you will alot of contestants for your contests. Not only contestants it will also give you a genuine backlink.
If your blog is new and you have started any contest then this post will surely help you.
Have a look :
If you have started any contests you can also submit your contest here.