It's hard to find something like that.. why don't you instead create a poll on the forum or a topic and ask people to answer.?
This way in around.. 4-5 days you will have.. the most wide spread data ever.. you could easily use it.. thereafter.
Since cryptocurrency is not that much famous of a subject to study thus you cannot find this big credible data .
Better you do it on your own.
Who knows maybe some other person knows better .
Best of luck .
This is unlikely to yield any conclusive results because forums typically revolve a single subject matter, so most of its users will have the same interests. If you take a poll of who pays with crypto here on Bitcointalk, for example, you'll likely get a much higher percentage than if you're polling random people in the street.
There are no extensive studies like this that I am aware of, sadly. Your best bet are Bitcoin payment processors, but I highly doubt they'll share sales data; I bet they won't even provide you a ballpark figure.
