How often does it show advertisements?

How many Wii U games are there anyway?

Would you expect the Wii U to do some sort of correlation (other people that own the same games A & B also own C, so you're probably interested in C)?

Here's a fun experiment idea. When you are around friends and the Wii U, only talk about games that came out at Wii U launch, ideally one you don't have. Like, FIFA Soccer 13 or something. Don't ever search for that game or talk about it away from the Wii U. After a week or so of that, see if you get an ad for it.

"We were talking about new games and I got and ad for a new game!" sounds like pretty standard, non-targeted advertising. Easily chalked up to coincidence. Steam advertises new games to me, some I'm interested in and some I'm not, but I don't think Steam is reading my brainwaves.