A contest can be a win-win, but there are factors to consider:
1. It should be easy for people to participate. Even though there is no more powerful word in advertising than “Free”, onerous rules or effort can make it free dollar-wise, but expensive time-wise and participation is inversely proportional to the effort required.
We ran a contest on YouTube over a year ago that asked people to create a video destroying a collectible stock certificate (it was more clever than it sounds) for RealStockCertificates.com. We got some notice and the winning video was very good, but the return was not worth the effort.
Lessons I learned: 1) Despite the legendary Viral nature of YouTube, unless you get very lucky, it still takes a big budget to make a large impact there, just as with traditional advertising. 2) Asking people to create a video, even on a video-centric site, is asking for a commitment few people are willing to make.
2. The prize offered should be very appealing. The Wall Street Journal recently had an article about contests on Twitter. One commonality of the successful ones was prizes with broad appeal, like an Ipod, or that appeal specifically to their audience (a super jacked up PC for a tech crowd).
3. Broad participation. Getting the word out to people who would be interested is a marketing challenge like any other. It is not true that if you build it, they will come.
We just started a contest. Our newest site, http://www.Buy-A-Web-Site.com, is a place for people to buy or sell full web sites or domains that are collectibles-related. The contest is using Twitter to notify Twitterers who use the key words collectible, antique and vintage that they can win a domain name of their choice (there are about 35 Domains that have those words in them) just by tweeting about a name they want and the contest.
We'll announce the winner here and tell you how it went.