Before you create your page you want to make sure your audience is represented on Facebook. You want to make sure you’re planning and creating a page that will generate the profits you desire.
One great place to start might be the collection of data published by iStrategyLabs, collected from Facebook’s Social Ads Platform. http://www.istrategylabs.com/wpcontent/uploads/2010/01/facebook_demographics_chart_statistics_2010.png
However, that chart and other charts found online don’t tell the whole story. Often the best way to see if your audience is well represented on Facebook is to log on and start browsing. Search for friends by interest. Look at other pages that are relevant to your industry.
You can also go through the motions of creating a Facebook ad. You’ll be asked to choose demographics for your ad. This can show you how many people your ad might reach. This is likely your potential audience for your fan page as well. (In fact, later, once your page has been created, you can create an ad to promote your fan page.)
Take a few minutes to jot down who your audience is for your fan page. Then spend some time on Facebook making sure that they’re present and that your efforts will be profitable.