why the hell is it a big challenge? I realize that yes, Internet connections can be flaky and you can't always control it,

but to me, this is easily solved by simply WAITING and let the buffer fill up. But in certain cases, the buffer will only fill if the video is playing.

when you hit play, throw up a screen saying please wait while we download your video so that it can play in an uninterrupted fashion.

but nah, they'll never do that because we've allowed attention deficit disorder to flourish throughout the land so we are simply unwilling to tolerate waiting a bit.

I used to do this ALL the time when apple quicktime trailers for movies first became big. Hit play, but then immediately hit pause and wait for that bar to fill all the way to the right. Sure, sometimes I got impatient and hit play sooner when I thought the buffer was going to fill before I finished watching the video, and yes, sometimes I got burned on this, but hey, it was on me, not on my ISP, or the video I was watching.

You can't even do that with youtube videos though, If i hit play, and immediately hit pause to wait for the buffer to fill, it never will, because they've got some stupid rule in there to only fill the buffer if the video is playing. Get rid of that stupid rule and allow the buffer to fill and I guarantee you the buffering symbol will go away for a lot of people.

@VoodooV if you're interested, more info here
http://arstechnica.com/information-technology/2013/07/why-youtube-buffers-the-secret-deals-that-make-and-break-online-video/

Ok, lets say you want to buffer the whole video...cool, youve just used up say, 10mb of bandwidth to buffer a video.

You get 600kb through it, and decide....nah, boring. Close the video.

You have just wasted 94% of the bandwidth delivered to you. Well played sir.

Multiply this by how many people dont finish a video through to its end? Thats a lot of wasted bandwidth.

so add in the bittorrenting to youtube and spread the bandwidth around.

maybe that's 94 percent wasted, but I would say only a small percentage of people don't ever watch the video.

pausing to let the buffer fill is optional anyway

Besides, I think @ChaosEngine is right and its more about back room business deals than it is about technology

and wasted bandwidth? we're talking youtube here, many would argue that it's already wasted bandwidth