Internet Retailer is running a story based upon a case study from our video hosting & creation vendor SilverDock.
This result is actually several months old and was included in Marketing "Sherpa's 2008 Wisdom Report":
We tested product videos on our top 10 revenue generating products. After several rounds of iteration improving the load experience, we settled on a 3 level test: no video, autoplay, and click to play.
Both video conditions resulted in conversion gains, but the click to play was dramatically superior. In addition to a 35% increase in conversion for the products with videos, the transaction funnel became much straighter. In other words, users who chose to click to play a video and then added it to cart were much more likely to complete the checkout.
Wedding related shopping is kind of a bellwether for purchasing processes that have to be perfect and are conducted socially. Product videos enhanced the sales of our best product spectacularly, reducing the chance of erroneous add to carts and increasing buyer motivation.
Time to go put some video on your site!