(Update: Voices is now #16 in the App Store. Here is a post about it http://taptivate.com/blog/voices-24-hours-in)
I saw a Tweet about getting free software, so I checked out this link.
By tweeting about the deal, you get a free copy of Voices for the Mac.
You enter your Twitter name, send out your tweet, and then they show you the avatars of everyone else who had done the same thing.
Pretty slick and easy marketing. A great example of how to use social media in your marketing efforts.