That was the challenge facing Verizon for its new 99 cents-a-day prepaid wireless plan.

With cell phone plans, people are used to thinking in terms of monthly costs, be it $50, or $80 or more. How do you establish value for a plan priced by the day?

Here's what Verizon came up with, working with Pearl Media, a New York out-of-home company: ice cream trucks.

One day last month it sent out Mr. Softee Trucks to promote the new phone plan. Every treat on the truck cost just 99 cents, about a third of the usual price.

Four trucks were sent out, one each to Manhattan, Brooklyn, the Bronx and Queens. In big white letters against red were the words: "99 cent ice cream."

That was sure to draw crowds, and it did. But also on the bright red trucks were these words: "99 cents does more" under the Verizon logo and on the door of the trucks: "More calling, More flexibility, More reliability, Just 99 cents a day."

"Basically, Verizon wanted to provide the people of New York with a unique experience showing how far you can get with 99 cents, all the things you can do with 99 cents," says Josh Cohen, president of Pearl Media. "Wouldn’t it be great if all ice cream was 99 cents?"

Verizon could have given the ice cream away, but that would not have created the same effect. The promotion tied in with the price of the phone plan to create a real sense of value. And since at 99 cents the ice cream was a real deal, then so was the plan.

But there was yet another benefit of the alternative campaign: the time folks spent waiting in line for the discounted ice cream. It was time spent looking at the trucks with their messages in big letters, and it was time thinking about what those messages meant.

To reinforce the message even further, the Softee servers handed out napkins with the Verizon logo.

Lines for the trucks, which were on the streets from 11 a.m. to 10 p.m. on June 23, were lengthy, running down the street and wrapping around corners.

It was a good day for Mr. Softee too. "The trucks literally showed a 700 percent increase [in the number of sales] from a normal weekday in New York City," Cohen says.