From Spam, by Finn Brunton, pg 67-68:
The business of phone sex is structured around arbitraging the different settlement rates—how much it costs to call a given country from the United States. A company in the United States leases lines in another country to route the calls and takes a per-minute cut of the settlement rate, with most phone sex calls routed through places like São Tomé, Moldova, and the Republic of Armenia. These millions of minutes of pay-per-minute activity were a significant source of income for the leasing countries: foreign pay-per-call operations were an enormous part of the traffic on Guyana Telephone and Telegraph (GT& T) circuits, for instance, making up $ 91 million of GT& T’s $ 131 million of revenues in 1995, and São Tomé kept approximately $ 500,000 of the $ 5.2 million worth of phone sex calls Americans made via their country in 1993, using the money to start a new telecom system. It is one of those strange macro/ micro moments that will recur on the fringes of spam’s history as lonely, sexually frustrated Americans unintentionally built telephone infrastructure for an island they’d never heard of off the coast of central Africa. 10
Mark Carrigan 