Actually, I find it more interesting that they are making money despite offering free network services for PS3 owners.
The big advances this generation is alternate revenue sources. Besides a variety of in-game advertising opportunities, the PSN services and Blu-ray seem to be coming along too. Can't wait to see how new services like Life and Home pan out.
In general, Playstation also enjoys some form of halo effects (cross-sell and up-sell). Some people like me went on to buy more Sony hardware as a result (PS2 was my only Sony product). It is said that PSP drives PS3 sales like how iPod drives Mac sales. I think if they continue to polish their software efforts, they should have a bright future ahead of them. The important thing is not only the software IP and unit sales, but the methodologies, organization, and economics behind integrated software + hardware businesses.
The only big hole right now is media integration. They are not as aggressive as I would like marrying media with Playstations so far (PS Store is a decent effort but not as inspiring given Sony's content heritage). User generated content is also unproven yet (Come on, LBP and Home !).
I like to read Stringer's interviews because they usually tell us what bothers him:
Stringer: CD sales will continue to decline. We are observing a fundamental transformation. Basically, the iPod has destroyed the album. It has created a singles industry in which artists are finding it much more difficult to create their own music catalogue. That's a shame for two reasons. First, there was a time when we made a lot of money with albums. Second, an album represents an artist's creativity, which is the sum of more than individual hits. We must therefore explore ways of giving musicians the same opportunity again.
I can understand their pain but am bemused with how they are going to solve the problem. The latest PS Home leak shows a shared music streaming service. Perhaps they are thinking of an online "full album" rock concert in PS Home ? If so, please hurry up !