This might not be the right forum to ask, but I imagine people in remote sites (like mining or offshore energy), and people in low-infrastructure areas, or people over satellite links or on aircraft wifi could be interested. Despite that, I've never seen such a service advertised.
I worked on this as part of my remote browser ~ 2 years ago, but stopped progressing the text-only mode due to complexity and apparent lack of interest. If there are people prepared to pay for such a service, I might get back to work on it. In any case I'll probably throw up a demo later on to whet people's interest, but who wants this bad enough to pay for it?
I like to think it's a no-brainer, save bandwidth to save money, but perhaps the loss of convenience of clunky text mode, or possibly cheaper and better remote site network infrastructure, makes it not worth it.
A tiny market segment with a cheap BATNA is probably not going to be lucrative.