Just a few prize tips for running successful contests
Make sure to give away something of value
Some ideas could include physical products such as an iPad, Kindle, or giftcards. These are usually good for generic contests that you would like to collect untargeted users. Because they will go viral (almost everyone wants an ipad) they will get participants mostly looking to just claim the prize.
Give away your own products for targeting
Other good items to give away are your own products! This is perfect for targeting a specific list. For example if you sell dog biscuits and you want to give away a lifetime supply of dog biscuits, chances are only other dog owners would be interested in winning that prize and would therefore enter your contest. Those folks would also share it with their dog loving friends and not just anyone.
Combining prizes are great too. Lets say you want to give away a free membership to your subscription site and also an ipad. This would make the value of your offer increase and get more participants to get involved. While still balancing between targeted and un targeted leads.
The most important thing is value of your offer. Be creative and think about what your potential audience would love and also would be ok with sharing to their inner circles.