MTN Revenues in Trouble?

Sean over at Sean's Investment Review details a revenue threat to MTN, Africa's largest cellular provider.

For the past year, the company's revenue from SMS text messaging (6.6% of total revenue) has been on the decline. It appears that a GPRS-based application called Mxit is the culprit. The program can be downloaded onto cellphones and allows users to text message other Mxit users at rates dramatically lower than those charged by MTN.

I'm assuming that Vodacom would also be seeing their SMS revenue under pressure thanks to Mxit. This is more bad news for Telkom, which owns a 50% stake in Vodacom.