No real point to this its just an observation and a rather loosely worked out one at that I have to admit. But if the population of UK is about 60 million, probably about 40 million are potentioal swingers (deduct kids etc). Roughly divide by two for couples is 20 million. Over 400,000 registered on this site alone means about 2% of the population are on this site alone .Taking in to account other sites and others who swing it looks like a fairly large percentage of the population are interested.
I guess what I'm trying to say is swinging looks like its more popular then I thought anway!
I thankyou.