Why is PlayStation 3's virtual world Home free? Because you lot keep buying virtual items.
Home, which enjoys 17 million registered users and contains 236 games, has suffered criticism from the press and gamers since its 2008 launch, but Sony has maintained its profitability through the sale of 7000 high-margin virtual items.
That, according to PlayStation Home director Jack Buser, is big business for Sony.
"If you look at the first quarter of this calendar year, we actually tripled revenue from the same time period of the year prior," he told Gamasutra.
"The business model works, and we like it quite a bit. It's one of the reasons we're able to offer PlayStation Home as a free service."
Looking to the future, Buser said the quality of games within Home will keep it growing.
"Games are the killer app for the platform," Buser said.
"I think once gamers find out that they have hundreds of games built into PlayStation Home, most of them free-to-play, [they will try Home]."
And what kinds of games will they be? Buser expressed interest in virtual item sales and free-to-play microtransaction-based games. Microtransactions are Home's "bread and butter", he said.
"Here we are in the console space becoming very comfortable, very familiar with the latest and greatest business models of the game industry, putting us just miles ahead of the competition in this regard."
Not everyone is convinced, however. Earlier this month Microsoft described Home as a "nice chat room" and "not an awful lot more".