Why did Ki Chikov buy so many dead serfs in Dead Soul?

1842, Nikolai Gogol published the novel Dead Soul. Chikov, a "scheming" speculator, came up with a set of tricks to get rich by selling short and taking advantage. He bought the unregistered dead serfs on the serf list at a low price in N city and its surrounding landlord manor, applied to the state for ownerless wasteland under the pretext of immigration, and then mortgaged the obtained land together with the list of dead serfs to the government for profit.