These advertisers are watching Twitter TWTR -4.22% and other social networks to see what topics are getting the most attention, and putting together short blog posts, tweets and videos that match those themes—in hopes that the online audience will become more aware of the brand and see it as relevant to their interests and needs. Then, if one topic isn't getting attention anymore, the companies can drop it without much fuss, and switch gears quickly to follow the next hot discussion. Consider what Bank of America Corp. did during the World Economic Forum in Davos, Switzerland. Experts from the bank's legal, social-media, marketing, advertising and other departments scanned 60-inch screens at brand agency Digitas Inc. late into the night to see what was trending on Twitter. Their mission: to promote the bank's brand among people interested in economic issues by publishing real-time content related to the conference. During a session on women, for example, with #davoswomen trending on Twitter, the bank's team tweeted a link to a Merrill Lynch paper about the growing economic influence of women. Get the full story at The Wall Street Journal