When StarCraft 2 was lauched, the installer (before Battle.net installer crapware) had a complete graphical visualization of seeders & leechers.
Reference: https://warcraft.wiki.gg/wiki/Blizzard_Downloader
Once I was using Blizzard's downloader to install something (StarCraft, Diablo, I don't remember), and it was kinda slow. I disabled P2P downloads and speed skyrocketed, and I said "Huh, this was unexpected".
When P2P downloads disabled you could see the list of CDNs you're downloading from and mine had a single IP on that list. It looked familiar. Then it dawned on to me. It was the Akamai server which we were hosting in our system room, at 15 minutes of driving distance. After a chuckle, I went to get a cup of tea, because that was entertaining than the game itself.
Then of course, I dived into whatever I was installing that night.
Edit: From the screenshots in the wiki, I remembered that the progress bar was red. It was possibly Diablo 3, then. However, I'm still not 100% sure about it.
However, these network operations (and CDN related stuff) are not managed by us, but by a couple of high profile guys next door. I knew we had an Akamai node, because the machines were shipped recently and we had a chat about it.
Funnily, some of the performance optimizations on Akamai's disk access algorithms (SSDs were not dime a dozen back then, so people were still optimizing for spinning drives) was apparently developed by a friend of mine, but I don't know any details about that.
To get the file out to 100s or 1000s of machine they would often use private bittorent to distribute the file out.
It was very controversial. Users were angry that software companies were using their internet bandwidth to distribute their software. Made a lot of people angry.
This was in an era of much more limited upstream bandwidth. The p2p nature was obscured from non-technical users in some implementations. So on and so on. I'm sure there are plenty of writeups from that era detailing why it was a bad idea.
These companies already used capable CDNs to distribute patches. It was a way for them to shift their CDN bill onto their paying customers.
Not everyone has the luxury of fully symmetric internet connections even in this age. Yes, my uplink speeds are absurd when compared to a decade ago, but when I ratio it to my downlink, it's still slow.
I have no comment on residential proxies. Somebody doing something in my name is unacceptable to put it very mildly.
If I understand the description correctly, microsoft still does this!
https://support.microsoft.com/en-us/windows/privacy/windows-...