Realistically looking at the numbers, the 360 is the better selling console of all three consoles. I'm not surprised.
When I worked at Target in the electronics section, these three consoles were making their first introduction into Christmas. So I believe it was around 2005 or 2006. At the time of their releases the Wii was already sold out due to lack of production with high demand. The 360 definitely had the best game franchises when they first released the console. They also had XBox Live to back on which is by far one of the best online gaming for consoles.
Target sold out of the 360 and the Wii. The PS3 was barely purchased. Those that purchased the PS3 said (at the time) it was a cheap Blu-Ray player. Keep in mind Target attracts between Joe Average gamer to Hardcore gamer.
Even after people know about the 25% chance of failure with 360s, they are still purchasing it. It's not scaring anyone away. It's the features that the Xbox has always had that attract these buyers to purchase it. When I get money first thing I am purchasing again is a 360. When I had a PS2, I barely used it to play some games. I always loved playing online. I tried the online gaming on PS2 with SOCOM and shit, and it was terrible. When I had the first Xbox that shit was fun to play on Live. They built and signified what online gaming is even if you have to pay for it. People will pay if it's good (see WoW).
It's kind of sad Sony builds a good product, but their emphasis at the time of PS3 release was the Blu-Ray player. They had nothing to fall on. No good games, shaky mediocre online play. What used to be considered a cheap Blu-Ray player is now obsolete considering the market has changed.