If you are getting a flood of traffic, anything you can do to establish a connection with people is vital. Keep in mind there may be some people who aren't willing to sign up for the service today, but might be willing to subscribe to your blog, sign up for a contest, etc.

Also your site is something that people may be willing to share with their friends more than they are willing to sign up for it themselves. You might consider making the social media buttons a bit more prominent. I might not be willing to login with Facebook, but may be willing to click "share this on Twitter" because my friends will think it is funny. (Obviously you should test this. My assumption may be wrong and the social buttons hurt things.)

You might also consider adding a bit of social proof to the site. A testimonial of a user or something like that. My first reaction is "I don't know if I'm comfortable adding their facebook application." A headshot and "wow this is wonderful" from a user might lessen that feeling.

By the way, you said you got a subscriber. Is this a paid service or are you referring to people to add your facebook application?