From #openttdcoop wiki
The Cashmaker is the name for the network built at the beginning of every coop-game. Mostly the most profitable cargo is transported (i.e. coal).
Only few terrain-changes are done and the tracks are unorganized to save money and to earn as fast as possible enough cash to start with building the regular network. Hubs are typically quick-and-dirty (see Ghetto Style Hubs) except near the primary drop. An inefficient hub is typically tolerable as the added delays are not intolerable and the network is not near capacity and unlikely to jam.