To put video online, most people run a VHS tape through a software editing system. During that process, most everyone chooses to compress everything, including the audio. Of course, to add salt to the wound, you've lost half your audio quality, as well. Viewers will get frustrated, fed up, and leave. Choosing the wrong media format.
Most people create web video files in one of a handful of popular software file formats.
They are made to be played by video players, such as Quicktime and Real Player. But Quicktime prefers .MOV files. And Windows Media Player prefers .WMV and .AVI files. The problem is, not all players on people's computers can run all the different file formats. The result is that many of your visitors well steam up and leave.