Redmond-based Smilebox is partnering with Hallmark Cards to power a new photo-based service on the Hallmark.com Web site, the companies are announcing today. It is by far the biggest deal in Smilebox's short history and one that could give it broad exposure and more revenue.

Smilebox launched in test form in March as a service that lets users insert photos into digital postcards, slide shows or photo albums, add a musical soundtrack and send them to others.

The company has 25 employees and received $5 million in first-round funding earlier this year. Its service is designed to appeal especially to people who enjoy online greeting cards and scrapbooking, and 85 percent of its users are women.

A basic form of the service is free; Smilebox charges small fees for users who want higher-resolution, printable and ad-free versions. Rather than directing its energies to luring people solely to its own Web site, Smilebox is trying to build a broad content-and-distribution network that includes other companies.

So far, it has six partners, and most, including Hallmark, are in revenue-sharing agreements.

"You could imagine the amount of money it could cost us to educate a Hallmark consumer on Smilebox directly," said Andrew Wright, Smilebox's founder.

Now, Hallmark is offering a customized version of Smilebox's service on its Web site, which saw about 6.5 million unique visitors in November.

Kim Peterson: 206-464-2360 or kpeterson@seattletimes.com