Rake
The room's commission on every pot played. Invisible in the moment and very visible over distance: in half an hour of play it is comparable to the day's result.
Rake is the share of the pot the room removes before the money reaches the winner. At NL100 it is a few percent of every pot with a cap of a few dollars. It is taken from the pot, not from profit: the loser of the hand paid his part too, through the pot he did not take.
In the moment it is $2 out of a $45 pot. Over distance it is a different order: across the series the room took 4.8% of turnover, $298 an hour from two tables, $24.85 per seat per hour. The sum of all players' results at a table always equals minus the commission: at a table of six, the room is the only one guaranteed to win.
An example from session 9
Over nine sessions I took 453 pots worth $4,803, and the room removed $231 from them. Before rake the series made $476.65, after it $245.62: forty-eight percent went to the room. Of everything the field lost at the tables where I sat, the room took 81% and I took 19%. If you get to choose, be the marketplace, not one of its users.
The same in business
Rake is a platform commission taken from turnover, not profit, and so it does not care whether you earn. A seller on a marketplace, an app in a store, a restaurant on a delivery aggregator pay it in a losing month too. A business has to be counted after rake: before it, everyone's numbers look good.
The whole hand is in session 9: “If you get to choose, be the marketplace, not one of its users”.
The other terms are in the glossary.