I see what you mean: Public transportation can be welfare-enhancing when there is enough regularity of travel between certain (networks of) points that throughput is increased when e.g. a lane is converted from road to light rail. The benefits of higher throughput would exceed the opportunity cost of the space being usable for fewer routes.
(tl;dr: it pays to bus people if they're all going between the same points.)
In that sense, if some major sites can exploit the regularity of the traffic they get to the point that they produce less load on the network per bit transmitted, that it's (not un)reasonable that the user be billed less for that site, though "free" is still questionable.
We should be careful to distinguish "bribing ISP for preferential access" vs "accounting for the reality of the cheaper carriage of one site's data".
(tl;dr: cheaper data rates can reflect corruption or legitimately lower access cost, and our reaction should reflect that.)
(tl;dr: it pays to bus people if they're all going between the same points.)
In that sense, if some major sites can exploit the regularity of the traffic they get to the point that they produce less load on the network per bit transmitted, that it's (not un)reasonable that the user be billed less for that site, though "free" is still questionable.
We should be careful to distinguish "bribing ISP for preferential access" vs "accounting for the reality of the cheaper carriage of one site's data".
(tl;dr: cheaper data rates can reflect corruption or legitimately lower access cost, and our reaction should reflect that.)