Any good plugin or CMS to Start Giveaway website?

I was trying to start a good giveaway website and started searching the web. I found kingsumo to be good but the problem with it is it counts the point even the fb page or fb share is not actually share, just clicking along the link only adds the point. So, any help will be really appreciated.

Socialmonails has something similar to Kingsumo. Might be worth a look!