In case you don't know what I meant by retention I meant the analytic that shows you how much of your videos is actually being watched. Here's the retention data for my latest video for instance. It's a great tool to see where viewers are dropping off so you can maybe consider cutting parts of future videos where you see big dips. Intros and channel animations are usually the worst killers.
Oh jeez! Ya I'm seeing a bit of a dip during my intro section! Might end up cutting those out!