Few terms irk me like the term "Viral". As in, "we've got a little money left - how about we use it for something...viral?" Or my particular favorite - the ad budget with the line item for "viral".
C'mon people. Word of Mouth is the original viral marketing, and it's been around a lot longer than forward-able video clips. Viral becomes viral because there is a perceived value - social, cultural, etc. - to sharing whatever the source material is.
And that's darn hard to predict. If it wasn't, movie studios would only release the films that do well. There wouldn't be remaindered bins for NKOTB. Because predicting what people like is...hard.
Case in point, 'Chocolate Rain'. You may well be one of the 3.1 MM people who've already grooved to it. (250,000 plays since last night at 9pm PST!). And I'd love to see the research reports and "pre-test" analysis that would have resulted in a green light on it from the marketing suite. But here's a treat (apologies upfront): act now and be one of the only 200K folks who've grooved to this spoof.
Or my personal favorite, "Internet Dream". It's the riffing. Soooooooo sweet.