Professional pages with custom “landing” or “welcome” tabs. This is the first thing someone sees when visiting your fan page for the first time.

Cincopa WordPress plugin

The welcome page could be interactive ; meaning it can display one thing the first time someone visits your page THEN display another thing AFTER they have “Liked” your page. You can offer your visitors something for free to encourage the “Like” then show them the details after they click on the Like button.