Remember when PSN was down and then came back, and Sony offered some somewhat shady compensation afterwards? It worked, for them.
While I'm not really surprised at all, it does kind of annoy me that Sony's backhanded marketing that they deemed "The Welcome Back Program" actually did what they were no doubt hoping for. If you don't remember, they offered up free downloadable copies of various games a few days after PSN began being restored and 30 days worth of Playstation Plus. The shady part of this was that a few of the free games were the original titles of some PS3 exclusive sequels and thus somewhat suspiciously doubling the nice offer as another way of marketing those other games.
Perhaps a slightly cynical viewpoint to take but considering they could have offered up any free games on PSN and instead chose specifically titles like Infamous and LittleBigPlanet; one game with a soon to release sequel at the time and another with a sequel that would directly benefit from this promotion it did seem a little lacking in overall good will. Yes Sony is a business and they need to make money, but after your service stops working and causes problems for people you don't go and try to trick them in the process of restoring their faith in your service.
I'm always a pretty jaded, cynical guy so I jump on stuff like this quite easily, but I think even the most die-hard of Sony faithfuls can agree a better offer could have been made. But that's all in the past now. What really matters is that it actually worked in Sony's favour. PlayStation Network users actually increased their purchases after the promotion and games like Infamous 2 and LittleBigPlanet2 did indeed receive sales boosts according to Sony. Dead Nation was another title also made free with the offer and users actually stated they would be interested in a sequel after having played the first.