Once means of transmitting payment were developed, phone sex turned into primarily a commercial activity, with customers (overwhelmingly male) and sellers (overwhelmingly female).Due to the potential for emotional intimacy between those who have engaged in phone sex, it is a matter of some debate whether phone sex is to be considered infidelity when involving a person outside of a committed personal relationship.
Nevertheless, phone sex should not be confused with prostitution wherein money is exchanged for real life sexual services or physical interaction.
The editor of High Society magazine, Gloria Leonard, is credited with being one of the first people to use "976 numbers", then "900 numbers" for promotional purposes and soon as a revenue stream in the adult industry.
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.
Unused minutes were rarely usable on a second call.
Originally phone sex services consisted of a managed network of dispatchers (live or automated) and erotic performers.