Despite the conventional wisdom that people won't watch commercials longer than 30 seconds, a new study by Invodo suggests that the length isn't as important to viewers as the content of the spot. If the spot is interesting, or provides useful information, viewers will spend more than 3 minutes with a spot. Spots that demonstrate how a product is used seem to be particularly valued - with viewers indicating that they will often watch those on multiple occasions, and helps them make a better buying decision.
Craig Wax, CEO of Invodo, concluded: "If anything, our research suggests that packing too much content into a shorter video may be a mistake. As long as the video is compelling and helps them make a purchase decision, most consumers are willing to absorb videos much longer than 30 seconds. Focusing on video content and quality will help brands drive business results."
Source - Length Doesn't Matter; It's What In the Video That Counts, VidBlog