The player: Stephanie Grossman, CEO of Digital Sidebar, a mobile advertising technology provider.

The play: Digital Sidebar is a mobile technology company that inserts content and ads into the so-called “white space” on mobile phones. That means when calls come in or when text messages arrive, Digital Sidebar’s technology can judiciously place content and ads on the screen of the phone. The material is short-form, snack-size and can be advertising- or media-related, such as an offer for a song or ads for concert tickets, Ms. Grossman said. “The idea is to engage consumers while they’re engaged, [such as] incoming and outgoing calls, and notification of incoming or outgoing [text messages],” she said. Digital Sidebar is about to launch a pilot test of its technology in June with one of the top two mobile carriers, she said.

The pitch: The key to success is to be circumspect with the frequency of the messages on mobile phones, Ms. Grossman said. “We don’t want to be the purveyors of the ad phone,” she said. “The goal is to have an effective solution for mobile advertising and the discovery of content.” Also, Digital Sidebar’s technology makes use of the moments when consumers are interacting with their phone rather than requiring consumers to go to a mobile Web site to see the ads or the offers.

In the mix: Digital Sidebar has already inked deals with marketers including Paramount, Universal Pictures and Universal Motown Records Group to deliver their content and ads on mobile phones. Digital Sidebar’s competitors include companies like Third Screen Media.

The money guys: Digital Sidebar raised $5 million in private equity. The company is launching the service now and expects to make money from a cut of the ad revenue.

The pros: Mobile ad spending will grow from $1.6 billion this year to $4.8 billion in 2011, eMarketer predicted.

The cons: Last week the Federal Trade Commission expressed some concern about delivering ads on cell phones and possible hidden costs for consumers. The FTC is likely to watch this business closely.

Background: Ms. Grossman was born and raised in Los Angeles and earned a bachelor’s degree at the University of California at Los Angeles. She has worked at Warner Bros., Court TV and Scripps Networks. She currently lives in Santa Monica, Calif.

Who knew? When Ms. Grossman was 12, she borrowed $700 and bought gold charm jewelry from the Los Angeles Jewelry Mart. She pinned the jewelry onto pieces of velvet, rolled it up and then sold it door-to-door—at a profit.