Many viral video networks
I know some companies that are deploying viral videos, the challenge for them is that theyre releasing them on more than one video network. Theres quite a few, from Revver, Blip, YouTube, Google Video, Metacafe, Grouper, and quite a few others.
I created a list of video sharing sites back in August, its already way outdated. If youre not sure which video site to use, you could always compare all the video sites in this side-by-side comparison.
Measuring still a challenge
The goal in todays distributed web marketing strategy is to get your content to go far, and have legs of its own. With that come challenges in measurement and tracking. It appears companies like VidMeter Tracker can aggregate instances of all forms of media, aggregate total views, as well as comments, making the job of a marketer a little bit easier. Although they track 32 video networks, Ill suspect that only about 5 really matter, and at the end of the year, only 3 will really matter.
Also, If youre just using YouTube, check out TubeMogul which apparently has robust reporting features.