Polls and Quizzes
You also can set up polls and quizzes, either in your forums or on other parts of the site (the latter is probably the better choice). This is a great way of involving your audience and encouraging users to return to take part in more polls or to view the results for previous ones.
Quizzes are a bit less common and, therefore, might be the more original alternative. You could even award prizes to the winners of these contests (see the next paragraph). Polling your visitors on their knowledge of certain topics discussed on your site will encourage them to find more information on your pagesand may get people to better appreciate your site and consider becoming members. Making only members eligible to take part in quizzes is another good way to expand your member base.
Be sure to announce poll and quiz schedules and results well ahead of time so that you will get lots of participants and, therefore, hits.