Comment by Manishearth

See: https://news.ycombinator.com/item?id=10791939

One carrier is already trying this.

Also, facebook isn't even financing the actual data (the carriers are), and the carriers' business plan (get people hooked onto the Internet so they migrate to a full plan) works on any form of "free limited internet" plan, where the plan is limited by speed or a data cap instead of by limiting what "Internet" means. Facebook is a third party which has wedged itself into this with extra deals; but the situation from the carriers' point of view shouldn't be much different if they set a free data cap or provide a free slow internet plan.