The bigger question is how the emerging encyclopedia wars will play out. Some observers, such as Wharton's Waldfogel, believe that Wikipedia has the potential to alter the entire business model for reference materials. "If enough people find that free information is an acceptable substitute for the verified and edited information in traditional encyclopedic sources, they will stop buying and using traditional tools," he says. "The question then becomes: Who is handling the process of gathering and presenting information, and are they producing a reliable product?"

At this point, there's also no proof that Wikipedia can succeed financially. So far, Wales has eschewed advertising and depended solely on contributions to keep the web-based encyclopedia afloat. Last year, the Wikimedia Foundation, which oversees the project, raked in approximately $750,000 in donations
( and pursued grants to help cover costs. Several large companies have also tossed their support behind Wikipedia, including Internet giant Yahoo! Currently, Wikipedia operates with a staff of only three paid employees.

Nevertheless, in addition to Wiki­pedia, the organization has introduced Wiktionary, the world's largest multilingual dictionary;­ Wikiquote, a compendium of quotations in more than three dozen languages; Wikibooks, a collection of free, open-­content textbooks; and Wikinews, which features stories based on feeds from news agencies as diverse as ABC Online and Al Jazeera. The latter is part of Wales's ongoing attempt to provide "different perspectives and not wind up as a slave to ratings." Wales also runs a for-profit business called Wikia, which oversees an assortment of online communities supported by ad revenue.