(This attitude still survives among some providers.) When public (mostly female) pressure forced the phone companies to stop providing this service to sex workers, a transition was made to a manual method: pre-paid blocks of time, 10, 30, 60 minutes, whatever the customer would pay for.
The incentives for providers were then reversed; rather than earning money from keeping the customer on the line (orgasm delayed), they earned more from bringing the caller to orgasm quickly, so as to move on rapidly to another call.
Phone sex takes imagination on both parties' part; virtual sex is difficult if the operator does not put the images in the head of the caller and the caller must be open to the pleasure as well.
The sexually explicit conversation takes place between two or more persons via telephone, especially when at least one of the participants masturbates or engages in sexual fantasy.
Each participant may engage in any type of sex act with one or both of the others, such as vaginal, anal or oral sex or mutual masturbation.
One or more of the participants may engage in autoerotic sexual activity, such as masturbation, possibly without physical contact with the other participants.
Once means of transmitting payment were developed, phone sex turned into primarily a commercial activity, with customers (overwhelmingly male) and sellers (overwhelmingly female).It is a matter of subjective definition whether participation of a third person without physical contact constitutes a threesome.This may relate to fetishes such as voyeurism or cuckolding.Some couples use a threesome as a way to develop a love triangle (ménage à trois).The people involved in a threesome may have any combination of gender and sexual orientation.