According to general logic, the profits of real estate agents should come from information service fees, transaction commissions and sales of customer information. However, in Beijing's housing rental market, the profits of housing agents mainly come from price difference, commission, so-called fines and various fees unreasonably withheld. 2. Take a one-bedroom case cut off by an intermediary from the landlord as an example. Assuming that the lease period is one year, the home appliances are complete and basically brand-new, the price that the landlord rents to the intermediary is about 2811 yuan, and the intermediary company generally charges the landlord one month's rent as the vacancy fee (in fact, in the rental season, the vacancy period is at most one month), that is, 2811 yuan; The intermediary rents it to the tenant at the price of 3,211 yuan, and charges the tenant one month's rent as the intermediary fee, with an income of 3,211 yuan. In this way, the ideal income of the intermediary is (3,211-2,811) * 12+2,811+3,211 = 11,811 yuan. 3. In addition to charging proper commissions and secretly eating the difference, some informal intermediary companies usually play word games in the lease contract, and then explain the details themselves after signing the contract. The most common means is to cheat in the column about "tenants bear the costs of water, electricity, gas, sanitation, etc." Generally speaking, in such contracts, "gas" is usually written as "coal, gas", and an inconspicuous pause means more than a thousand yuan for heating. Tenants usually understand "coal and gas" as natural gas, but in fact there is a gap of a pause.