You can see it as 90% of their traffic being caused by iPlayer, or as 90% of their business being due to the content provided (at no cost to them) by iPlayer.

You can see it as 90% of their traffic being caused by iPlayer, or as 90% of their business being due to the content provided (at no cost to them) by iPlayer. An exaggeration, of course. But the principle stands. If (eg) streaming video were not so popular, far fewer people would pay for home internet access, and far fewer would pay a premium for 'high speed'. ISPs are in business because they provide a means to reach content which those ISPs do not have to pay for the cost of producing. The notion that they should be paid by content providers so that they can charge content consumers to access that content is... nonsensical.