100MB is lot of data, even 10,000 products would only be about 1 MB of actual storage. Also there are many things being logged that can be removed or reduced using normal DotNetNuke settings. The real problem with database growth is that SQL server doesn't delete data. You have to manually (and regularly) shrink the database to keep everything in order.

That brings up an interesting point about DotNetNuke itself.  I think it is missing two important features – database backup and shrinking. Ideally they could be scheduled to run on a regular basis, but they should be available for manual functionality. I would also like to see some sort of status page that gives an overview or snapshot of the DNN data. I just ran into a database reaching the allowed limit and it breaks DotNetNuke pretty quickly. Once I realized the problem and shrank the database everything returned to normal.

It would be interesting to hear about other experiences along with their typical usage and storage requirements.