I dont know if the ads have helped but our PS3 sales have definatly gone up in the last month. We havent sold a 360 in about 3 weeks now at the gamestop I work at (and still sitting on 6 halo systems to top it off). Of course WII's are gone instantly (6 gone in 10 minutes last week) ,but we have no ps3's now we sold our entire stock over the weekend (10 systems between all designs...including 3 refurb 60 gigs)... everyone coming in to ask was asking about Wii's, release date of Mario, PS3's and then about that cool looking "middle east looking game" for the ps3 (aka assassins creed)....
Then again I am a mall store so we get A LOT of people who are not hardcore gamers compared to our other 3 strip mall stores in town so who knows.