There are generally three types of users on the forums:

1) Users who are active and post on a regular basis.
2) Users who post occasionally when they are experiencing a problem and need help.
3) Lurkers

Most of the forum activity comes from group #1 which is a very small number (less than 2,000). This is typical for most communities (social networking communities are an exception) where a small number of people actively participate in the conversation and most others register for a specific purpose (in this case, to download the software) and then only participate occasionally. Because of this, there is really no co-relation between the forum posts and registered users.  

It is definitely inaccurate to say that the rate of new users drop down from month to month. Since Jan. 2003, the number of monthly registrations has consistently increased, always above 10,000 since June 2005. We recognize though that registrations are nothing more than a "point in time" indicator with duplicates and anons. We therefore give more credence to other metrics which inidividually don't say much, but in totality, more accurately help us understand the DotNetNuke adoption worldwide. These include:

- SourceForge downloads
- Newsletter delivery, open and click-through rates
- Deployed public sites
- Site usage statistics

While it is true that you can download the software directly from SourceForge.net, keep in mind that DotNetNuke is used by people with a wide range of technical skills. Many of them are not familiar with SourceForge and linking from DotNetNuke makes it easier for them to download the product. The registration requirement is not unduly onerous and even though the data may not be 100% accurate, gives us another metric to track DotNetNuke adoption.

We regularly receive queries from people about DotNetNuke metrics, especially those whose business relies on DotNetNuke. We have spent much time in the past few weeks working on what is easily the most detailed set of DotNetNuke metrics ever compiled. We will publish this report soon, both as a free edition for anybody interested in high-level DotNetNuke metrics and a commercial edition with more detail that is suitable for businesses.

Nik

Excellent questions Alfonso.  I'm interested in this also.

One thing to help explain part of it, although admittedly I don't know the real numbers either, is that Go Daddy and other Hosters provide DNN for free to their accounts.  I know that Go Daddy tells their members with questions tocome here for support, so that is one reason for the high amount of new registrations, but low participation.

Are you trying to understand the overall adoption of the framework, or are you more interested in knowing how many people participate with feedback and help on a regular basis?