Some other answers have covered this, but I think it’s worth repeating. Forum PHP is a very useful tool, but it is a mistake to use it for all your discussion-based websites. The reason is that using it will make you ignore the actual behaviour of your user base. Forum PHP cannot process meaningful queries.

The most it can tell you is when someone posted a reply. Trying to get your users to register and use the login system is futile. You will be much better off finding a way to track their actions and their post history, either through cookies or some other method.

As long as you can query their behaviour (rather than their booking dates or whatever), then you can do most things that Forum PHP was originally designed for. As a bonus, you’ll get much more accurate traffic statistics, as your statistics will include actual traffic and not just user registrations.