Here's my reply from another thread on the same subject:
The key is pacing! This is basically how quickly and consistently you're delivering the goods! In YouTube this manifests mostly in how you choose to edit your video. How many shots you allow to linger on for several seconds.
On the other hand, it is entirely possible to have a thoroughly engaging and entertaining video that doesn't use lots of cuts, or even any at all. I can think of a couple youtubers that are so well-spoken and funny that they sometimes do a video in one take and it's not boring at all. Most of us aren't this talented though, and the longer we let shots linger, the more boring it becomes.
Stephen King once said "Kill your darlings." Sometimes it doesn't feel great to cut huge chunks of what we recorded, but that's often what it takes to end up with a tight, cohesive, well-paced video. (and I'm quite guilty of this problem myself, I assure you)
Good luck!