(Forbes.com)(Forbes.com)

Most people would say that their favorite picture of their spouse is invaluable. Jason Stitt can put a precise dollar figure on it: $2,000 (US). That's how much he's earned by turning a single snapshot of his wife into stock photography.

Digital cameras have transformed consumers into an army of amateur photographers, most of whom upload, tag and share photos online. But are they selling? Stitt is. He's among the thousands of amateurs who are discovering how to turn their expensive hobby into a profitable part-time pursuit.

Stitt, a graphic designer, got his start in 2003 when he uploaded some beach photos from his honeymoon in Hawaii to iStockphoto.com, now an online subsidiary of Getty Images handling digital media. He sent in about a dozen shots, and to his surprise several started selling.

These days he takes hundreds of pictures during two shoots a week from a home studio in Southern California and puts up the best for sale on Shutterstock.com. Selling stock pictures "is getting very close to being a full-time gig," he says.

Point, shoot, cash in

Stock photography is an increasingly lush business. Case in point: Last year, stock photo Web site iStock paid photographers $20.9 million in royalties on $71.9 million in revenue. In 2006, the Internet start-up was purchased by Getty Images for $50 million. Last February, Getty was sold to San Francisco-based private equity firm Hellman & Friedman for $2.4 billion.

Given all the digital pictures floating around on the Web, surprisingly few people are trying to cash in. A recent survey of U.S. consumers sponsored by the stock photography site iStockphoto suggests that most people simply haven't been exposed to stock photography. Of the 1,000 people surveyed, only a quarter had heard of "stock photography." Even so, a majority of them said they are aware that there are legal rights surrounding the use of photographs and video they might download on the Web.

For the record, stock photo, video and audio is ready-made content that people or companies can license for their use. Artists have licensed their work since the beginning of copyright law — but those kinds of exchanges are far easier to do with digital files, pixels and clicks than they were in the old world of film and paper contracts.

For consumers, selling stock photography online means that they can pick up a high-quality picture, video or audio clip for as little as a dollar. Pricing usually depends on size and quality. Once the licensee purchases an item, it is considered "royalty free," meaning they can usually do whatever they want with it. The online merchant handles the financial and legal elements and credits the artist automatically with a cut.

"When we first started [in 2000], people thought we were crazy," says iStock chief operating officer Kelly Thompson. "We have 3.5 million registered users on our site now and over a million paying customers. That's far bigger than most people ever thought the stock market could possibly be."

Much of iStock's success in selling digital stock can be attributed to creative tinkering with the economics supporting digital rights.

"We've found that people don't really mean to be malicious," says Thompson. "It's the same as iTunes: If it's easy and affordable, they don't mind paying for it."

The players

iStock isn't the only game in town — it competes with other Web sites trying to woo stock photography dilettantes. Other large suppliers that will help you pawn your pictures include Dreamstime.com, Shutterpoint.com and Stockshop.com.

Jon Oringer started Shutterstock.com — the service that Stitt now uses — as a digital storefront for his own work in 2003. The site has since grown to host more than 4 million pictures.

"We've had small companies use them for brochures and Web sites. We've seen them on billboards and bus enclosures," Oringer says.

For artists, the royalties start small but can grow. At Shutterstock, photographers get paid 25 cents per download and more as the artist passes certain earnings milestones. These micro-payments can add up.

"There are photographers making close to $10,000 a month," Oringer asserts.

Stitt isn't quite in those ranks yet, but he's a good example of how a hobbyist can thrive part-time in the stock photo market. His top-grossing photo was one of his first — a picture of his wife, Ruth, sitting under the sun in a straw hat. The photo has been downloaded more than 3,500 times.

"A lot of the stuff I do, I just cross my fingers and hope that it sells," Stitt says. "Today I did a shoot with a female model lying on the floor surrounded by jelly beans. It's kind of out there, but we'll see how it works out."