Bill Arconati on why Wikipedia isn’t the ideal example to follow when using a wiki in business:

As the most widely-known wiki deployment in the world, Wikipedia has done a lot to raise the public’s awareness of wiki technology. However, that success is a two-edged sword for us wiki evangelists. That’s because Wikipedia’s popularity has shaped the public’s notion that wikis are only for building encyclopedias and that the controversies surrounding Wikipedia are applicable to all wikis.

For more on this, see How to do a Better Job of Project Collaboration Using a Wiki.