Suddenly, a simple text search service that usually trades in minor trivia or local movie times was thrust into the role of being a trusted source of news. "Our whole guide team had to get on this," adds Marshall. Once the New York Times had confirmed Jackson's death, ChaCha was able to issue a final proclamation into its automated answer system to go out to the 100,000 questioners.

Let that be a lesson to mobile media. We're not playing around anymore. People are expecting answers, the right answers, from your little start-ups.

ChaCha is the free and ad-supported mobile search service that uses human "guides" to answer questions. Which raises its own basic question: How does such a thing scale? Marshall tells me that growth has been dizzying. ChaCha has served over 150 million answers thus far and gets about 15,000 new users a day. It reaches about 2 million monthly unique. Nevertheless, the service has not expanded its guide staff recently because it relies increasingly on automating replies to common queries. About 80% of the questions that come in get some form of automated reply, although often farmed through a human "expediter." "If they don't have a database answer it goes to a specialist," Marshall says. No one is making a living as a ChaCha guide she admits, but a lot of part-timers, at-home moms and other domain experts who like the challenge provide the human engine.

The predominantly under-25 audience for ChaCha is a perfect target for Hollywood marketers, which represents one of the strongest categories of return advertiser for the company. Paramount recently used the small and conversational text ads in ChaCha SMS replies to move the needle on the summer premier of the "Transformers" sequel. A countdown campaign for the film started less than a week before opening day. Whenever users send in a question, they get an SMS acknowledgement that includes a tiny text ad. In this case, ChaCha played with the messaging. "In five days revenge is coming" read one of the daily countdown messages, and in others the service said it was in the process of "transforming" the user's question into an answer. Users were driven to the "Transformers" mobile site to get trailers and images, but the effectiveness of the ChaCha campaign also hung on the service's persistent reminders and the conversational tone in the messaging. Users could engage in conversations and questions about "Transformers" characters and movie times.

In all 1 million impressions were served for the "Transformers" property, and according to a post-campaign report from InsightExpress, the effort paid off in a 27% lift in brand awareness and 10% lift in purchase intent. "It seems as if it had a direct impact on unaided awareness, which is a key metric," says Mike Rosenberg, VP national advertising, Paramount Pictures. Given the success of the original "Transformers" film, "awareness was never a problem for us," he says. "The unaided awareness and the ability to make this movie an event was the main goal, and clearly to drive last-minute knowledge the Wednesday that the movie was opening. Everyone knew it was coming, but did they know when it was coming?" He adds, "Mobile was an immediate response. We could reach them directly as a reminder." Rosenberg sees in this success some good precedents for leveraging mobile with sequels and may use the approach next year when "Iron Man 2" hits.

Marshall says that entertainment is a natural category for her youth-oriented demo, and these clients have been coming back for multiple campaigns. But is 1 million impressions really all that much, given the scale of the "Transformers"' massive multimedia push? Is a solution like this really capable of being more than a curious add-on to campaigns? Marshall argues back that ChaCha's 2 million monthly uniques are so well concentrated in the youth demo that it rivals the under-25 slice among otherwise larger entities like RockYou and Hulu. "When you talk about eyeballs and the ability to reach this demo, we become an interesting play."

Interesting, to be sure. ChaCha's conversational approach to marketing has always fascinated me. Company strategists have a strong grasp on the ethos of the handset and the person-to-person language marketers must learn to appropriate here. Even if much of the process is automated, their ads wisely adopt the voice of one young person talking to another, and the natural tendency is to reply in turn. Why aren't mobile banner ad designers taking some lessons from this yet?

Marshall says the company is working on refining its own targeting. Much can be inferred by the nature of people's questions, but now ChaCha is intercepting users with surveys that grab gender, exact age and location in order to improve targeting. What about the new competition from the paid SMS search service from the well-advertised KGB.com? Marshall says the competition not only legitimizes the category but almost always gives ChaCha a boost when the rival is mentioned in the press. "We get a mention as the other free service whenever KGB gets mentioned. It's been very good for us."

ChaCha's creative approach to SMS ads is worth monitoring. I send in a message here or there just to see if I hook an interesting ad bug. ChaCha will be launching back-to-school campaigns for BestBuy, IKEA and Palm Centro soon.

This commentary is insightful. I recommend it to others.