1. Content management extends the "shelf life" of your site.
The typical shelf life of a website is somewhere between two to three years. Most sites get built, and remain pretty much the same over the few years of their use. At some point the site becomes embarrassingly old and desperately needs to be redone. At this point the old site is thrown away, and a new site is built. Such rebuilds are usually more expensive than the initial build since the new site will usually do more than the original. A database-driven content management approach allows a site to be improved incrementally simply by making changes to site templates. Such sites can evolve over time, thereby extending their "shelf life" well beyond that of static sites.

2. Content management avoids the "loss of opportunity" scenarios common to static site development.
Because content management based sites are easily adaptable, you can implement all the new ideas you get for your site even after it has been completed. Often companies get great ideas for their sites very shortly after going live. This is common because it's often not until you use a site that you begin to see additional possibilities. With static sites, site-wide changes can be extremely costly, so such ideas usually get tabled until the next redesign. This means that between rebuilds there are missed opportunities that could have maximized a site's effectiveness. With a content managed site, site-wide changes such as adding new sections, implementing extranets, or a host of other possibilities, can be easy integrated into the site without having to rebuild it or wait for years until a redesign becomes necessary.