Is there any data on how many otherwise vanilla couples participate in the male chastity/ female keyholder dynamic? Either as a lifestyle choice or as occasional play/experimentation. Is it 1 in 100? 1 in 1000? As one who is thinking of ways of how to introduce this to our life, it would be interesting to know….
Excuse me. Sorry. edit. As I thought, lots of hits to the query, but no data specific to the particular question.
I don't think specific data exists. You could look how many cages are sold on amazon or how many got hacked. That doesn't tell you how many were gag gifts or used once put in a drawer. Not as if polls are taken like a census. Even then how many would be honest. It's one of those unanswerable questions.
I agree with @Mr_anonymous that it can’t be discovered or even estimated really, but it’s certainly not a completely obscure activity because of the number of businesses that specialise in making high quality and very expensive cages. No one would buy these for a laugh, and the businesses clearly make enough profit to sustain the manufacturers’ livelihoods. So if what you’re looking for is a way to “normalise” this lifestyle choice, what you can say is that there’s evidence that “a lot of people” take it seriously enough for proper craftspeople to be involved.