Web video and televison, while both video-centric, are very different marketing tools. TV commercials are fast paced, very restrictive, and expensive. You have a limited amount of time to effectively deliver your message, and paying for ad time is extremely pricey. That doesn’t even include the cost of production itself.
But perhaps most importantly, television is not targeted advertising. Your message could be seen by millions of people, but most of them won’t be looking for your services.
Web video on the other hand is much more open, and is a smaller investment. You can take all the time in the world to deliver your message, although I wouldn’t recommend more than 2-3 minutes. You are in full creative control of your final product, and most importantly you can use web video to target specific markets. It’s much easier to put your message in front of the people that are actually looking for your services using web video than it is using television.