Feed slimes. Collect plorts. Get paid.
The plort market is a network of buyers and sellers of plort across the galaxy. Ranchers use plort market machines on their ranch to send plorts to the market for sale. Ranchers are paid immediately when depositing plorts the plort's current market value.
Plort market values fluctuate and some of the more savvy ranchers will hoard certain plorts for days when sale prices are high, especially rare plorts.