With these features, Plone makes it easy to keep content updated, which again assures the value of the intranet. It also has a quite a few of the so-called intranet "killer apps" built-in - the functionality that makes people use the intranet every day. One of them is the ability to quickly and easily locate other employees, with associated portraits.
Another interesting point about Plone is the consistent quality of the design and solutions used, especially in combination with the aforemetioned killer app:
Because they will be using the killer app just as much as everyone else, these designers will internalize the good usability guidelines embedded in its design, and will be reluctant to launch contributions with significantly lower quality. - Nielsen Norman Group, Intranet Design Annual 2002
This study also highlights several other important considerations that are core strengths of Plone, namely:
* Single sign-on.
* Limited use of graphics. (intranets should use graphics minimally, and to add to content, not detract from it)
* International focus.
* Templates based on predetermined styles.
http://plone.org/about/old/articles/plone-intranet/
