I've covered this pretty extensively for MyBroadband in the past, so I'll try to help out...
Sauce: http://mybroadband.co.za/news/intern...gal-in-sa.html
I've only heard that the exclusive rights thing was an issue in other markets before (e.g. when Netflix launched in the UK), but according to SA's recently launched legal alternative, Vidi, exclusivity is not the problem, cost is.
More sauce: http://mybroadband.co.za/news/intern...ing-in-sa.html
In other words, there is no exclusivity on VOD content (anymore?) and the issue is with licensing content for a specific region.
Some speculation on my part:
I'm sure this whole regional licensing thing is derived from exclusivity deals from years ago - that have since lapsed - and became "exclusive license to broadcast and offer on catch-up type services in region X" instead of "exclusive rights to distribute in region X".
Could have been MTN legal (Axxess' new owner), Times Media Group (Vidi's owner), and a bunch of other companies that rattled their sabres too.
From what I've read about HBO's whole HBO Go / #takemymoneyhbo situation you're on the right track. It is much more profitable for Netflix and HBO to license their content to platforms such as DStv exclusively than it would be to enter a market like South Africa themselves.
If they were to compete against DStv with their own subscription VOD service, the implication is that they (Netflix/HBO) would have to charge less for their exclusive broadcast rights. Maybe there's even a risk that DStv wouldn't take the content at all (though with a show like Game of Thrones that's risky, I reckon).
Ugh. I don't feel like I've covered the issue particularly thoroughly in this post, but it's getting too long, so I'll wait for feedback before rambling on.