The benefits for people in the cities are definitely there: better communication, higher flow of information, more possibilities.
The benefits for people in the bush are, as far as I can see, virtually zero. Giving "free Internet to all those poor people in some African village" may sound great to a Western audience, but to me it signifies an utter misunderstanding of rural Africa.
In the West, the Internet has brought on a social and economic revolution, with much changing for the better. But to think that simply giving African villagers free Internet would bring them the same benefits is utterly misguided (at least as things stand at the moment). Here's why:
1) Electricity: smart phones need a lot of electricity. How do you get that into places that aren't hooked up to the grid? First you would need a program to distribute solar cells or something of the sort to provide the necessary power. (Note that I think this in itself would be a much more laudable goal than free Internet - you can do a lot more with electricity than you can with access to the Internet.)
2) Hardware: You need to get those smart phones into the village in the first place, and once they are there, keep them in working order. (Despite extreme heat, dust everywhere, and a host of other technophobe conditions.) Note however that many villagers do in fact own a cell phone by now, although they tend to be good old-fashioned, cheap and durable Nokias.
3) Education: many, if not most villagers are illiterate. The Internet is a text-based medium. If you really want them to benefit from the Internet, fix the education systems in their countries first.
4) Language: most villagers do not speak English/French/Portuguese fluently. The percentage of sites in a language they understand (if they can read) is infinitesimally small. Therefore, the actual benefit they have from Internet access is much reduced.
5) Oral tradition: Almost all of Africa has an oral tradition, not a written one like the West. This means that there simply is no culture of writing things. Very few books are being written in Africa, the number of magazines appearing in any given native language range from zero to perhaps five. This partly has to do with the aforementioned lack of education, but a lot of it is really a cultural artefact. Again, the Internet is a text-based medium that includes very few sites in local languages. And if (almost) no one is going to write new sites, that is going to stay that way for the foreseeable future.
6) Programming?: Some people suggest that given free Internet, the villagers could teach themselves programming to earn a living. This is ludicrous. Even for those who can read and write, many have never even seen a computer, let alone have the funds to buy one. And how are they going to get paid if they (as is usually the case) don't have a bank account, and the nearest bank is 200km away?
7) National service providers: the last point is an economic one. Despite what people in Europe and America may think, there is actually Internet available in large parts of Africa. Local service providers are expensive, unreliable and often incredibly slow (we used to be glad to get a 5kb/s connection). But they are local. If some big company from the West pushes in with an offer of free Internet for all, the national economy is going to suffer for it. (It's happened before with the clothing industry in Tanzania, that was all but destroyed by western "charity clothes".)
I have lived most of my life in Africa, I love the continent and its people. Of course I want them to develop their countries further. But seriously, giving free Internet to villagers is just about the dumbest thing you could do right now. Yes, eventually they should get good Internet, absolutely. But that is problem #241 on the list, and we're still working on problems #25 through to #43. Let's fix the education and health systems first; help them develop good agricultural techniques and fight corruption; build up solid infrastructures for transport and electricity, or any other of the myriad of things that they need, URGENTLY.