This is pretty standard marketing stuff in 2014... If I were running the Xbox marketing department I'd start firing people if they WEREN'T doing this.
There are entire startups whose job it is to set up advertisers and YouTubers with this type of arrangement - look no further than FullScreen, BigFrame, et al...
One is that you're correct, it has been happening for years within the industry, so it's kind of weird to see an article almost in the style of an "expose" on the practice.
Two is that it really isn't getting huge market traction. Or it wasn't at the time when I was working more closely with it. It was considered more like a value-add or diversification strategy alongside other media buys and not a primary strategy.
There are entire startups whose job it is to set up advertisers and YouTubers with this type of arrangement - look no further than FullScreen, BigFrame, et al...