Booking Engine: Folder or Subdomain?

[Discountvc]

For an online commercial site, would a booking engine/reservation system best fitted in a subdomain structure or a folder?

We have always preferred folder for blog, any other content. A reservation system with lots of search results, lots of variables, we are leaning towards a subdomain in a WP site.

Pro's and Con's are highly appreciated!

[PattiFousek]

I personally would use a subdomain for tracking purposes. A folder may make tracking visits, roi, etc. difficult.