Audio in video - quality control FTW!
Artists! Don't stop the quality control of the music / sound when you give the video editor the file for the song he's about to use for your video. Use the best quality you can (and by that I don't mean to upsample or anything like that, just lossless master files). If the video editor has been using a rough mix or a older version of the mix (not mastered even) make sure he gets the final version as well and actually replaces the file!
And when you get the video back... you know what to do ... another round of quality control. Listen again, make sure that the sound is actually in stereo (for instance). It always amazes me how people surprisingly often manage to screw this up and make the sound in videos mono. Oh and ... after you upload the video, ... you guessed it, another round of quality control. Make sure it's how it is supposed to be, that the audio and video are actually in sync (for example) If you can't hear the difference between mono and stereo for whatever reason (because of your monitoring or other reasons) ask a audio professional for help. I'm of course happy to help you out anytime :)