Getting back to the original question... I think it is more common than what we would like to think it is.
I can't put a figure on it but BB has been offered as an incentive to continue as a regular on several occasions...
This includes girls that say "No BB, you will be blocked etc.," on their profiles....
As far as I am concerned, I am not as naive to think it doesn't go on with a large proportion of girls out there.
Quite. My experience was 2 out of 2 long term regulars: that surprised me. But not as much as the 5 'first or near first-daters'. That was absolutely unexpected.
So, I've found that it available 100% on regulars (admittedly just on a sample of two regulars), but 35% - pretty much 1 in 3 - on all others (a group of fourteen), where, without exception, it was not only not advertised but is nominally discouraged in the strongest terms.
And all operating in what appear to be reasonably respectable situations - not on the street, no tramlines, desperate offers or outward signs of mental health issues.
This ought to be very useful information to those who have felt it was a small minority activity, or who are keen to protect themselves - and particularly for those who express horror at the prevalent risk, but who are nevertheless a little more relaxed about actually taking meaningful precautions themselves.