You may call their business a real business but fact of the matter is that "real business" is handing them huge losses every quarter, so if they do not improve things drastically soon, that cash will not last them long.
Also, bookings were up. I think it's important to note that after FB's updated S1 everyone had worried since Zynga comprised less of Facebook's Q1 revenue. What all news outlets failed to note is that FB credit associated purchases didn't go down but actually ad impressions on Facebook's part. It's possible Zynga is trying to drive pageviews of their own network rather than Facebook. (Check the S1) [2]
[1]: http://venturebeat.com/2012/04/26/zynga-beats-q1-earnings-es...
[2]: http://sec.gov/Archives/edgar/data/1326801/00011931251217567...