Facebook is a tool for local businesses to get the word out, attract fans and connect with your market.
There are people who are having such phenomenal success using Facebook they are deleting their non-Facebook sites.
I do not recommend you rely 100% on Facebook for your internet presence any more than I would suggest you only have a blog on a “hosted for you” provider. The reason why is the same–you just don’t have control! You don’t officially own the site and therefore you are at the mercy of the provider and if they feel you are violating their terms of service or they don’t like your content they can actually take your site down.
This happened recently again at Facebook and it is creating a stir as several of the recent victims are reputable sites.
The claim is that these sites are violating copyrights. However, there is disagreement over whether or not the violation claims are accurate or not, and the process that Facebook goes through to verify the violations.