I am the Marketing Director and a Founder of 22Social, where we help thousands of entrepreneurs to launch or grow their business on Facebook. It's more than likely you are here because you know who I am, and you need my personal and undivided attention. At 22Social we used ONLY Facebook to launch our business. We acquired over 15,000 new users in less-than 90 days with less than $1000 in ad spend - without a website. I keep it simple and focus on the least amount of work that yields you the greatest results.
I use the FB Login App to collect FB Verified leads thru an App on my Fan Page.
See this video which explains http://youtu.be/5tjVNf9H_Uk.
I have mainly offered a free software trial - 7 day ecourse, or registrations for live hangout events which I also host on my Fan Page.
It has been very effective, generating over 40,000 leads in the last 15 months for one of my businesses. The best part is that 90% of the traffic is a result to a high viral coefficient.