Vulcan Love Slave is an erotic holoprogram that involves the participant and a female Vulcan who has thrown off her kolinahr practices. It was very popular at Quark's Bar. Grand Nagus Zek was particularly fond of the program, and made it an effort to "enjoy" the program whenever he visited Deep Space 9. (DS9: "The Ascent")
It is possible that the Ferengi fascination with the idea was implanted in 2252 on the Enterprise NX-01, when Ferengi came in contact with T'Pol who was pretending to be a slave "trained in the arts of pleasure." (ENT: Acquisition)
Two sequels were later created: "Vulcan Love Slave, Part Two: The Revenge" and "Vulcan Love Slave, Volume Three". (DS9: "Doctor Bashir, I Presume?", "The Emperor's New Cloak")