[staticsafe]

If I was a betting man - backbone providers don't do this (sell to advertisers).

It would be costly to maintain the interception/analysis infrastructure required for such data collection.

I daresay it would cost more than what they would make off the data.

[Goopplesoft]

Thats an interesting bet. If they isolated to the subnets they sell off to ISPs (i.e exclude datacenters and such) what do you think would contribute to the cost/benefit difference of the two?

[staticsafe]

That is still a significant amount of traffic to analyze and store data for.

I don't want to speculate further as I don't know what margins for transit providers in NA look like.