This is an interesting question, and certainly something I've thought about for such comparisons. I didn't do this one, but we obviously talk around the office about how to tackle articles like these.
What would the correct proportion be to use, though? Last year
Cisco reported that 66% of all Internet traffic during 2013 was video (excl. P2P). How accurate would it be to apply that to SA VOD users, though?
Until we have an answer, at least this way we can see how the base costs of pay TV and VOD services in SA compare. Anyone reading the article can then apply whatever multiplyers/weights they feel relevant to their situation to see which is best for them.