IMO: It's a social networking site which means the value of it's advertising space is significantly reduced. Due to SMS it's got a high cost per user. If they find a viable business model they are going to have a lot of competitors. I can't afford to charge content producers because that would quickly drive them to a competitor.

Which is why they don't have a competitor. It still looks like a crappy businesses that's at the mercy of the wireless industry. EX: If they could make money from SMS traffic face book would take about a month before they had a system like this running.

Or they can just do an SMS subscription plan, based on usage. First 10 are free, thereafter it's $5/month.