Alan Schulman has a good view on what to do with the viral video's:

Viral video push is a big bonus to a well-conceived and executed media plan, but it's not in itself a substitute for a big brand Idea. And don't confuse trends with trendy. The trend is consumer as creator, not consumer as creative director. If we use it properly, as some consumer researchers and fan culture monitors are doing, the consumer as creator trend can provide lots of valuable insights into how people perceive and interact with brands, how much cultural currency those brands posses, and their real relevance to different segments. This is the trend to draft off of -- not the trendy.

Read the full article here.