Andrew McAfee offers several specific examples of business problems addressed by a wiki, prediction market, online community, discussion board, Innocentive, etc. Here’s the example that made use of a wiki for employee onboarding:

Problem: How can we bring new hires up to speed as quickly as possible so that they become effective employees and stop bugging people with all their questions?

Use a wiki. Office supply company VistaPrint initiated a wiki in an attempt to capture what a new engineering hire needed to know. Because this knowledge base changed so quickly, the company felt that any paper-based solution would quickly become obsolete. Within 18 months the wiki grew to contain over 11,000 pages placed into 600 categories, all of them generated by employees themselves rather than a professional knowledge management staff. It became a dynamic and up-to-date repository of the company’s engineering knowledge.