NEW YORK (AdAge.com) -- Although his nonprofit Wikipedia made him best known as the selfless guru of wisdom-of-the-crowd publishing, Jimmy Wales has a second site designed to make as much money as possible. Called Wikia.com, it has become a sprawling universe of thousands of wikis on nearly every imaginable subject. It now logs more than 500 million page views a month and has a growing stable of blue-chip advertisers. Many marketers have begun to explore wikis as vehicles for product promotion. But, as Mr. Wales explains in this 10-minute interview with Ad Age digital editor Abbey Klaassen, several deeply ingrained flaws in their thinking often cause their wikis to fail.