Max Levchin's PayPal is forecast to process more than 40 million U.S. dollars in transactions in 2007, and now he is looking into a new way to make money off Internet widgets -- high-tech shorthand for the mini-applications planted on the personal pages of online social networks and other popular websites such as Google.

Levchin's latest startup, Slide Inc., has emerged as the No. 1 widget maker to date, mostly because its programming tools have made it easy for people to add more pizazz to the pictures and videos decorating trendy hangouts like MySpace, Facebook and Bebo.

Monday, the 32-year-old Levchin will take a bold leap forward, or backward, when he inserts advertising into the mix for the first time.

"On the surface, it seems like a risky idea because what if (users) don't want advertising in their widgets?" Levchin said. He concluded his idea would only work by making all the ads "user-initiated" -- that is, the marketing messages only appear if users voluntarily choose to blend a marketing campaign into their own personal widgets.

Levchin and Slide's senior advertising director, Sonya Chowla, insist the approach isn't as far-out as it might appear. They note that for years consumers have willingly become walking billboards by buying clothing promoting the brands of major corporations like Nike Inc. and Coca-Cola Co.

"We are really good at getting people to take things and include them on their social networking pages," Chowla said. "We think we can persuade our users to become brand ambassadors."

Lisa Weinstein, a managing director of ad agency MindShare, said Web surfers have proven they will distribute advertising online by steering their friends and family to commercial clips posted on YouTube.

For the approach to work with widgets, advertisers and their agencies "will have to do it in a way that adds value to the experience, rather than interrupting or disrupting it," Weinstein said.