I worked customer support for Blizzard Europe for several years until about 2012. At the time they ran their own infrastructure co-located in ISP data centres. It was very important to Blizzard to have as much control of the quality of the user gaming experience as possible, with control of their infrastructure being a large part of this, and I would be very surprised to hear this philosophy of theirs has changed.
Then again, I don’t know for sure what they’re doing these days.
I think they moved it back to in-house servers when it went live, though, and dropped the server rates from 60hz to 20hz. Kind of a shame, the difference was very noticeable.
The comment by Bill Warnecke seems to indicate that some of the Overwatch fleet is hosted on AWS.
AUS players have a jsfiddle they link around which grabs the current IP ranges for AWS so they know what to block to be able to play on NA servers. They do this because the local playerpool is much smaller, to the point where they cannot climb to very high ranks without playing overseas.
That's one game.
The largest game, by a large margin.
I attribute my slightly better English vocabulary to Diablo 2 and other games of that time.
Good news nonetheless, early days though...
Almost all the major retail ISPs in South Africa openly peer at NAPAfrica (https://www.napafrica.net/), mainly to pick up Akamai, Google, and more recently CloudFront, but also to bypass expensive local transit costs from the local 'carriers' (Telkom/Openserve, MTN, Vodacom, Internet Solutions etc.).
As far as I know, only the mobile networks (some of whom are building out FTTH networks, but with relatively limited market share) don't openly peer there: - Vodacom - MTN
https://www.napafrica.net/traffic/ NAPAfrica currently does ~500Gbps of traffic. Approx 4 years ago it was ~10Gbps.