Flexibility

DotNetNuke has the potential to be anything a developer, armed with Visual Studio (of course), can think of. It can be a simple website, to a full-blown CMS, to a robust control panel. It can help you manage skins on a global, site page and even user level. I am not just talking about the "Master Skin". Even the individual elements (articles, containers, blogs, content blocks) can be skinned on a site-by-site bases to give each site a unique look.

Support

DotNetNuke (www.dotnetnuke.com) has pretty good starter documentation on the web but it's real support backbone is in the forums. Not only does DNN have forums … searchable forums … dating back a few years but there are other forums out there too.

http://www.dotnetnuke.com/tabid/795/default.aspx

http://forums.asp.net/

The community is pretty tight so be ready to feel like a newbie for quite a while (I still ask the 1D-10T question once in a while).

Development Work Flow

Someone did their homework when they made DotNetNuke. They really understood what the modern process is for small-medium sized websites (not to saying that large websites couldn't take advantage of DNN). The objectives are always the same: time to market, scalability and more functionality then you have budget for. DNN helps you, as a developer, make that happen with surprising ease.

Budget-ability

The people paying the bills enjoy this one. DotNetNuke allows you to make engineering decisions during project planning that reduce cost.

Warning to bill payers: Every time you reduce cost, you reduce functionality or increase time to market.

BUT….you can lessen the effect of those losses by choosing where to spend your development time. See Community for how this does this.

Community

The DotNetNuke Community is big, loyal (to DNN) and smart. There are exceptions, but most "DNN Gear" (skins, modules and utilities) you buy at the major DNN sites work pretty well. Most of the modules and skins you find can easily be changed to fit your scenario.

Choose wisely. Some of purchases are no brainers. You buy a pretty website skin and then use it.

But other more complex modules don't have the out of box functionality that you need so you either have to develop it or start over from scratch. I think of every DNN purchase as a patch. If it works out in the long-term, GREAT. If not, I'll fix it or move it to my solid state storage.