Analysts like to make bold predictions about the growth of mobile advertising. Most have overshot reality.But at least one slice of the business appears to be catching on, according to marketers: ads sent via text message. A growing number of companies are using cellphone text messages to lend more interactivity to their ads. For instance, Coors Brewing's Coors Light beer recently added a text-message component to its traditional sponsorship of the NFL Draft. Football fans opted to receive draft alerts, and each message contained a squib about Coors Light. Read the full story on WSJ.com.