What are the variables that lead to establishing the correct price to charge the guest on that given day, for that given room and with that given service? These questions are the basis of hotel Revenue Management: if it were a mere matter of arithmetic calculations, a program within which to allocate the various rates to be applied would be enough. However, Revenue Management for hotels is something more: it is the product of a philosophy whose tariff theorems are decided by HotelsTOO with the occurrence of variables not only external to the hotel but also internal to the hotel itself.