These two venues should be used together. You should create a showcase to highlight your product or service and then use Facebook as one of the ways to promote it. Showcase Central Facebook integration features make this easy to do.

Showcase Central and Facebook also differ in the length of time people can see information.

A showcase remains unchanged and relevant no matter how many people have accessed the page. A Facebook wall is constantly being updated and older posts are soon lost. By posting links to your showcase to Facebook on a regular basis you get the best of both worlds.