Leonard recorded her own voice informing callers of the contents of the next issue of High Society magazine before its publication.Later she recorded others such as Annie Sprinkle "talking sexy".
In concept they have a lot in common with platforms such as Ebay: the seller provides the picture(s), description, and sets the price, a percentage of which is kept by the platform.
In the sex industry, similar platforms emerged facilitating the selling of used panties and other odoriferous garments, and for "cam" video sessions, in which the customer, for a fee, can direct the woman on the video screen, and for a higher fee, have a private connection (no one can see caller or provider except each other).
All have some way for a provider to post a picture and some text.
Big platforms as of 2016 are Niteflirt, Talkto Me, and My Phone Site; the latter also includes provision by which a manager, with the consent of the providers, could have a virtual shop with many providers under them. Customers had a variety of payment options, and pages of providers to choose from, sometimes with voice samples available.
Once means of transmitting payment were developed, phone sex turned into primarily a commercial activity, with customers (overwhelmingly male) and sellers (overwhelmingly female).