Today's Wall Street Journal has an incredibly important article, "Advertisers Use Social Media to Promote Brands in Real Time; Advertisers Watch What's Trending—and Craft Content to Match."
Essentially, advertisers first go where the people are, i.e. they watch for what's trending. Then they produce content placing their brands in the center of the action.
This builds on already-established best practice:
1. Go where your customers are (don't force them to your website)
2. Declare who you are
3. Speak in their language
4. Follow cultural norms
5. Actually contribute something to the community
This strategy is so smart and it's very much like how you network at a party. Go up to a group, find out what they're talking about, and then say something about that, working a mention of your brand in.
The analogy for me is sports. I will never understand the Super Bowl or March Madness, but I know enough to know that they could come in handy every now and then.
* All opinions my own.