Contests in one form or another have been a part of marketing for decades. They are effective because consumers will trade time, information and even money for a chance to win a bigger prize. It is natural evolution of marketing for smart small business owners to take their contests to social media.

As I started researching contests on Twitter, I discovered they actually have guidelines. And while they are fairly loose, Twitter does explain why the rules exist:

• Discourage the creation of multiple accounts: If users make lots of accounts in order to enter a contest more than once, they’re liable to get all of their accounts suspended. Please be sure to include a rule stating that anyone found to use multiple accounts to enter will be ineligible.
• Discourage posting the same tweet repeatedly: Posting duplicate, or near duplicate, updates or links is a violation of the Twitter rules and jeopardizes search quality. Please don’t set rules to encourage lots of duplicate updates (like saying, “whoever retweets this the most wins”). Your contest could cause users to be automatically filtered out of Twitter search.
• Ask users to include an @reply to you in their update so you can see all the entries: When it comes to picking a winner, you’ll want to see all the contestants. If the updates include @username mention to you, you’ll be able to see all the updates in your mentions timeline
• Encourage the use of topics relevant to the contest: You might decide to have users include relevant hashtag topics along with the updates (like #contest or #yourcompanyname). Keep in mind that hashtag topics need to be relevant to the update; encouraging users to add your hashtag to totally unrelated updates might cause them to violate the Twitter rules.