If you’ve got something to market, there’s nothing like finding a group of consumers already interested in what you’re selling. The search marketing industry is built on what writer John Battelle has called “the database of intentions”: Figure out what people are looking for, then serve up ads they’re likely to find relevant to those desires. Google made $5.2 billion doing just that last quarter.

Of course, even in this digital age, people go looking for things in places other than the Internet. When they’re out and about, they often hunt for a business or service via phone, often using directory search. Several of these voice-recognition directories have started selling audio ad space for brief voice spots. If you’re asking for a taxi service, you might hear a 15-second ad for a competing service or even an ad for a car-rental agency.

If you’re in a hurry to get to your listing, that ad is more annoyance than assistance. Research shows most people are calling mobile directories to reach a specific business and get their hours or location. And at this point, it’s hard to know which callers will find the ads valuable and which will see them as a waste of time.

But one recent phone-based campaign aimed audio ads at a very highly qualified audience. The ads didn’t run in directory assistance but on the phone hotline for MovieTickets.com. And they zeroed in specifically on callers for tickets and local theaters showing “Iron Man”, the movie hit made from the Marvel Comics franchise featuring Robert Downey as the playboy-turned-crime fighter Tony Stark.

For the first two weeks after the early May “Iron Man” release, callers who dialed 877-789-MOVIE and told the voice recognition engine they wanted tickets to the hit movie received this message: “Like Tony Stark? See more of him in ‘Incredible Hulk’ in theaters on June 13. Press 1 to get a text message reminder.”

The campaign, put together by entertainment marketing agency Ignited and running on the Apptera voice platform, is designed to create big buzz for the summer’s next big comic-book blockbuster, a new movie version of “Hulk” starring Edward Norton as Bruce Banner, the physicist with anger management issues.

“The idea is that hundreds of thousands of people can be walking around with this ‘time bomb’ on their cell phones, and that the day before this movie they’re interested in comes out, all these phones will suddenly start buzzing,” says Randy Haldeman, chief marketing officer for Apptera. “It’s pretty darn cool that I can get notified at the right time of something I’ve expressed an interest in. That’s pretty powerful.

“We’re pitching it as a way to get personal with someone who’s passionate about a particular subject, service or movie.”

And of course, Apptera hopes to get you to call for tickets—and hear another ad. Haldeman says the company has been supplying the voice-activated platform for MovieTickets.com for more than a year now while waiting for traffic to build to a level that would permit some measurable entertainment campaigns.

The “Hulk” campaign was something of a test case for Ignited and Universal, the movie’s producers, and was put together in quite a hurry. “We were three days before the ‘Iron Man’ opening and we were pitching our overall services to Ignited, trying to be as vanilla as possible,” Haldeman says. “They hadn’t realized that a service like ours could target by geography, movie genre, rating or name.”

During the two weeks of the “Hulk” pre-release campaign, MovieTickets.com received about 100,000 phone calls nationwide, of which about 30% were for tickets to “Iron Man”, Haldeman says. And of those 15,000 callers—all of whom heard the Apptera ad—about 3% texted in to be notified on June 12 that “The Hulk” opens the following day.

Interestingly, about half the “Iron Man” calls were from landline phones, a fact that surprised Apptera, which runs voice-menu 411 services for other mobile directories and is accustomed to having the large majority of its calls come in wirelessly.

“I guess I can understand it,” Haldeman says. “You’re home on Friday night and you’re planning what you’ll do that evening.” It did mean, however, that those callers couldn’t opt into the notification and simply got a standard ad informing them of the June 13 opening. But Apptera has the ability to ask landline callers if they want to get a reminder call to the phone they’re currently using or would prefer to opt into the alert with another number.

Haldeman speculates that the call platform could be used effectively to market one movie to another’s audience even when they don’t share a character like Stark. “In the future, we could ask if people wanted to be notified about other comics-related movies such as the new Batman or ‘Spiderman 4’,” he says. “Or if they’d like to hear about the openings of other action-based movies generally.”

Studios could also use the platform to engage interested fans by sending opt-ins a text response that included a clickable link to a WAP microsite for the movie.

Finally, Haldeman theorizes that the Apptera platform could let content producers leverage interest in movies to market related entertainment products—for example, offering callers seeking tickets to the new Indiana Jones flick a chance to text in for a discount on the upcoming DVD release of “National Treasure 2”.

One interesting plot twist to the “Hulk” campaign built on “Iron Man” buzz: The two movies are from different studios, although both the comics they’re made from are both Marvel titles—hence the character crossover.