If you want to drive Likes of your Facebook fan page, here's a simple way to promote fan interaction with exclusive content. We'll use Paul McCartney's Band On The Run tab as an example.
1. Add a Static HTML tab to your fan page.
2. Replace CONTENT FOR NON-FANS with a message that tells your fans what to do, eg. "Click LIKE above to unlock exclusive content only available to fans." Be careful with your language as you're prohibited by Facebook's Terms of Service from saying "Like to download."
3. Replace CONTENT FOR FANS with whatever you want: A streaming audio or video player, download link, etc. Use HTML / CSS to format your tab content nicely.
In the Paul McCartney example, the tab will appear as follows to non-fans.
Once the fan "likes" the fan page, exclusive content is revealed.