The principle is the seller appropriating for themselves a value-driver that was previously part of the consumer surplus, without offering to exchange something of commensurate and enduring or time-series value in proportion to the time series of payments. It reeks of friction and parlor tricks to get you to miscalculate the cost / benefit situation.

Compare to a "land grab" or "rent-seeking" behavior. Also compare to "financing". It may be economically efficient to establish bargaining over the value but it matters asymmetrically to the parties to the transaction who is assigned property rights and who is renting.