By all accounts, hotel attachment is an important indicator. Roughly speaking, this is the percentage of bookings for trips of more than one day that contain a lodging component. A higher ratio means better data for negotiations and risk management. If the hotel booking is made with the air booking, there may be transaction fee savings. If it's commissionable, that helps fund travel management services. It can increase preferred supplier utilization. Travelers have only one contact to make in the event of changes or disruptions.
Definitions of attachment vary. Some . . .