Hard evidence no in terms of validated demographics? No, especially since it is hard to tell whether new users are Bitcoin users are not without them mentioning it, but it is pretty apparent to me that many of the new users are not Bitcoin users. Answering their questions about how to get their payments out (they have often never heard of Bittrex, Poloniex, Coinbase, etc.) makes that pretty clear for example.
But you don't know if their bfs are blocknerds who have been mentioning Bitcoin for years.
I saw many blogs explaining that females were coaxed into it by their Bitcoin bfs. It is like they get to make their bfs happy and make themselves some cash at same time. But what about the ladies who signed up and only earned 3 pennies. Do we hear from them?
Of course some are that, but not all. Many ages and backgrounds are represented. The apparent demographics are just much wider than Bitcoiners.
Once it gets large enough that real studies can be done I'm sure we'll see better numbers. Or we'll see that growth plateaus once people one-degree away from Bitcoin are tapped out. That won't take long.
You've probably read more blogs than I have. I remember some girl from Hong Kong and another from China. How is she doing?
At this point the weakest part of the site is that there is no working following feature, so I have no idea how anyone is doing even if I found their initial posts interesting. The whole thing is one big firehose, I just puck out posts more or less at random to see a sample. I have also hired a staff of 10 people to find posts for me to read according to my instructions, but obviously no one expects the typical user to do that.
That will improve; organizational features are in development, but the developers are very overworked.