For existing advertising networks there would be one more competitor. I wouldn't expect any business that caters to the auction model to replace that model with this.

Traditionally, good advertising has been a way of "extending the content." A magazine about computers would have ads related to computing. A magazine about fashion would have advertising related to appearing stylish.

For publishers who don't care about extending the content, nothing would change. For publishers who care about it, there would be one less available slot on the toolbelt.