A hit counter is programmatic and stores its counts in some persistent medium (database, file, etc). You can build them any way you want to.
Commercial page tracking software works in different ways. You'll have to consult with the manuals of each package in order to understand what they are capable of. If your content is selected through a query string value and the tracking software can discriminate complete URLs then you may be fine with whats available. However, if you want more specific control over the statistics generation you may need to roll your own analyzer.
-Peter
compiledthoughts.com