I love the concept and the look but I've given it a quick test and there may be a flaw. I don't think there is any verification to check that people have actually carried out the extra entry actions (liked, followed, shared on social for example).
I've entered a competition, clicked all the options to share and like on social so I can get more entries. However I've not actually followed through and shared or liked anything and it has still counted the extra entries.
It would be great to get verification of the actions to make sure people follow through and really help the giveaways gain more traction.