Revenue → Agents & companies.
For the organisations that book with you repeatedly — a construction firm hiring utes every month, a travel agent booking on behalf of clients.
Recording them as a company keeps their bookings together rather than scattered across individual customer records, so you can see what the relationship is actually worth.
Worth doing when
You find yourself recognising a name, or being asked for a single invoice covering several hires. Until then an ordinary customer record is enough.