Suppose you are trying to optimize a massive video streaming service (youtube, Netflix, that sort of thing), with 1 billion users (exactly 1 billion). Assume that your average customer has 78 ms of latency (thats a real number I calculated using some Verizon data). Using https://support.google.com/youtube/answer/1722171?hl=en calculate how much data is stuck in transit for 1080p and 2160p video with 5.1 Audio (use 35 Mb/s for 2160p video) with 50 million simultaneous users. If you wanted to buffer enough to cover a very poor case like north America to India (266ms) how much data do you need? Estimate bandwidth costs per user in both cases (companies like rack space offer bandwidth pricing data, but its up to you to research and source the data). Assume that you get the best rate available for data.