Why You Should Have An Intro For Your YouTube Video
The biggest thing that can help establish your brand and engage your users is to create a nice video intro. Intros are meant to be short, not annoying and are to establish who you are. Avoid doing the full 30-second intro with dubstep playing because most users will simply skip that intro instead do something short about 5 seconds or so that displays your logo in a nice fashion maybe with a nice animation a good example is GameSpot.
The intro is about 2 seconds it shows the logo, and the name of in this case the show "News Update" its fast we know everything about the brand we need too and it works. Traditionally you are given the longer intro numbers of 15-30 and here is why that doesn't work.
Most of your viewers don't want to watch a 15-second advertisement before the video they surely don't want to sit there for a 15-30 second intro with loud blaring music that can damage their ears if its not the same volume as the rest of your video.
So keep your logo simple try not to go more than 5 seconds, show your logo and give it a nice transition, animation, and sound so it feels like a natural progression to your video.