If one video stream to one user uses 128 kilobyte per second out of your 100 megabit internet connection 781 users can watch that stream at the same time. However, the ISP will charge you per transferred gigabyte each month. So let’s say that you serve 781 users that video 24/7 in a full month of 31 days … It will be 100 megabit divided by 8 to get 12.5 megabyte. So it’s 12.5 megabyte per second. That’s 750 megabyte per minute. That’s 45 gigabyte per hour. That’s 1 terabyte or day. So around 31 terabyte traffic per month. (If you use this much bandwidth you will get a discount but it’s still not going to be
Now, that’s just for 781 simultaneously users.
What is we need to serve 781000 simultaneous users?
Now, this far we’ve only been talking about one video on repeat 14/7. What about 100000 videos and enough programmers and computers to design as system that lets each and every user choose any video whenever they need to? Now you suddenly have thousands of servers and harddisks running in a couple of hundred places on earth 24/7.
Now this is for you to provide your users 100000 different videos even before you start to pay content creators for their hard work.
Also, you need to be available 24/7 so now you have to make backups, redundant servers on different location that can take over in case of an accident, dedicated internet connection (being alone on the internet cable is not the same as sharing it with 100 other sites) and a whole lot of other things you need to take care of.
What about offering the 500 million videos YouTube offers their users?
… and all of this cost is paid out of your pocket?