The point is that Nintendo saturate TV with adverts which have gameplay shots and people having fun.....the end result of which is that when the average person who's not really a gamer goes out for a console it's that imprint that Nintendo have made that comes to the fore. The Sony ad is for gamers really, and it'd hardly change the mind of anyone who doesn't really recognise the characters involved. Sony need to advertise to sell, not advertise to pat themselves on the back or make gamers go "Oh Sony....you guy's!"
Okay, here's an example of a Kevin Butler ad for a more "wide appeal" game:
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It has humor, it's silly, but it lists a lot of features of the game and shows off some gameplay footage.
Or this one:
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They advertise the games and their humor. Also "back patting" is just a less flattering way of saying "advertising the good aspects of their game". What makes a Sony ad where they say "The Playstation 3 is so awesome it can do this, this, and that!" counted as "back patting" and a Nintendo ad where they go "The 3DS is so awesome it can do this, this, and that" counted as "advertising to sell"?