If you're trying to encourage people to post on your forum, then running a competition can encourage people to begin a whole new posting schedule bringing a sparkling new lease of life to your community. Of course, get it wrong and you will pretty much end your community and burry it deep in the cold, cold ground.

What to avoid

Spam is the last thing you want on your forum. And if you offer prizes for the top posters that is what you will get. It doesn't matter if you lay down tons of rules about the quality of posts and how long they have to be. People will post loads.

Setting a word limit is not appropriate anyway. Sometimes a response of only a few words in the most appropriate post especially in response to a question another user has ask.

What does work

The aim of your community is to attract quality posts, as its quality posts which will attract new users and keep old users coming back. So it is only sensible that you offer prizes based on the best quality post.

A lot of forum competitions offer prizes for the most original post. You could also offer a prize for the longest post although this can encourage people to go on and on. The only real solution to this is not to tell your users about the competition but unless you know what you are doing this can end badly.

The prizes

When thinking or prizes to offer your users, make sure that they are appropriate to your users. A teen message board is not going to be whipped into a posting frenzy if you offer a subscription to the Financial Times. Similarly your mainly 40 year old board is not likely to be on the look out for the chance to win Super Mario.

Take into consideration also that the benefits of running the competition must be worth the prize you are offering. Don't give away you 40" wide screen television when your forum only has 4 members who only post every few months.

Conclusion

The trick to running a good competition is to take time to think every aspect of it through. How many users are going to take part and what are they going to do? What is the competition going to cost you? Is it worth it? Weigh up the costs and benefits and you will have a great competition that will elevate your forums.