I've been working on a passion-project for a while called Pi Day Challenge - it's a site designed to inspire people about math and celebrate 3/14.
One thing that I thought about tonight was whether or not I should direct users to like the app/fan page (http://facebook.com/pidaychallenge ) or the site itself (http://pidaychallenge.com ).
What's the best practice in a case like this - app or site?
Upsides I see to liking the app url:
If you're looking for link love, I think a +1 button on your site is the way to go. Facebook likes to your URL provide No Link Juice. If you're looking to build awareness I would go to the facebook page, if you are trying to move apps, maybe the URL is a better choice.
I'm with choosing the URL method.
That way it can help you gain publicity easier. If a person can view your site and (likes it), they will look for the mobile app as well.