I trust facebook.com (sort of), so I put information on there such as my likes. I don't trust just any old site I stumble across on the Internet. So there's no way that I'm going to register for your application with my Facebook account.

However, after some use, I may find that I do trust your application. Then I might be ready to click "Connect with Facebook". (Although that's very unlikely, as I haven't even done this with [Netflix][1], which I've had for years).

So the best you can do is:

1. Provide your users with a **way of connecting Facebook after they have signed up**, and let them know about this during registration (show *"You can always connect to Facebook later"* on the sign-up page).

2. **Occasionally remind** users of the benefits of connecting Facebook **in a non-obtrusive way**. (Occasionally in the content of some of your pages, display a message like "Connect with Facebook and see what your friends are [watching/reading/whatever it is people do on your app]! *We will never post anything on your wall without asking.*" with a *Connect Facebook* button.

3. **Advertise on Facebook** to get potential new users to come to your site from Facebook.

4. **Accept** that some (probably most) people just *won't* use Facebook on your application, and **find another way to collect information about their preferences** (like showing movies or books and allowing the user to check the ones that he or she prefers, or perhaps rate them).

5. Make sure you have a **privacy policy** that is clear, easy to understand, and easy to access about *exactly what information you get* from Facebook and *how you will use that information.*

  [1]: http://en.wikipedia.org/wiki/Netflix