For many people in poor countries, the smartphone is their computer. If nothing else, these people use smartphones to log in to Facebook and use it. That's a computer.
Low income individuals also will not care about smartphones. It is not expensive to get a smart phone, I believe most of them come free now as part of 2 year contract. The thing that is expensive is monthly phone + data plan bill.
Without exception, every internet cafe I went to (a lot) was overflowing with locals doing one of two things:
1. Chatting on MSN
2. Facebook
Phones aren't phones anymore. They're pocketable computers with a phone app.