How big is the instructional video market? Pretty big... if you are the distributor. I can say for a fact that at $50 a pop, it basically doesn't pay for producers. Think about it: Can you produce a video - from script to upload - in an hour or two? Well, I should say, can you produce a quality video in a couple of hours? Here's a bit on how Howcast makes a bajillion dollars distributing your videos: How Big Is The Instructional Video Market?

Note that I'm not saying you can't make money doing How To videos - you most certainly can, especially on ad revenue for popular spots. But it's hard to make a popular spot if it's not a really popular topic and, by definition, if it's a popular topic, there will already be a How To video about it. Also, it'd help if you were a sexy 19-year old co-ed and willing to reveal a little cleavage in the thumbnail. Just sayin'.