Here's a nice crisp post about how video can make a huge, quantitative difference to your online marketing efforts.
A few highlights:
1. Website: Boost Information Retention and Purchase Intention...Prospects retain a lot more information from videos than from text-based content—95% to 10%, respectively
3. Emails: Drive More Click-Throughs...Adding video to an email increases click-throughs by 200–300%, according to Forrester.