Having been in the lifestyle community for well over 17 years , attended many clubs , parties , hotel takeovers , etc . And belonged to a number of fetish oriented websites I can tell you with near certainty it is under 5% . I have a degree in mathematics and know that while unscientific websites like this are a self selecting sample of the general population. In 17 years I have searched through many profiles and only twice come across some nobody we knew outside of the lifestyle . That being said I think many women , and a fair number of men would be shocked at the underworld of sex that exists . From swinger parties to swingers clubs , to gang bangs and bdsm scenes . But in a larger metro area of over 5 million , even 1% means 50,000 people are participating.