For one, they tried hard to support every possible video format for upload (as opposed to, e.g., Google Video, which was much pickier about what it would accept

For one, they tried hard to support every possible video format for upload (as opposed to, e.g., Google Video, which was much pickier about what it would accept). In general, they nailed the "just make it work" factor. (Subjectively, I remember YouTube being the first site that made me think, "wow! video on the internet! it works!". Ironically enough, this is no longer really true -- half the time YT starts buffering part way through the video (sometimes never to go finish w/o a full page refresh), & the other half the time you get a disruptive pop-up covering 20% of the screen. Bah.)