I'm also aware that Naspers is developing a lot of content for WeChat, something in the line of channels you can subscribe to or something. I think you can compare it to what Mxit did(or tried to do) years ago, but at that time I believe the tech was not there yet.
I also think they might have a gap in the African market. My gardener has a smart phone. He asks for mp3 and videos and I know he is on Whatsapp. But I don't see Whatsapp trying to supply content yet, might change in the near future with the facebook deal.
If WeChat can get people like him on their platform and supply content to him for a small fee they have a very big market. Also I can see he is willing to spend money. I just wonder how willing is he to spend money on digital content.
Btw, "Hallo" from a fellow South African.