This is by no means a quantitative study, but I live in the U.S. (in a fly-over state, none the less), have very little connection to the arts and every friend I can think of, off the top of my head, knows who banksy is.
It's obviously a pretty self-selected population, and I mean, I haven't formally surveyed all of my friends, but there you have it, for what it's worth.
I like Banksy, but there's no way my mom knows who he is, which is the important thing. There are more "my moms" in the U.S. than there are "your friends", in other words.
That's true, and like I said, none of this is a quantitative assessment.
I think phrasing is that way is misleading, though, there are more "my friends" than "my mom" even though they each have a "my mom."
I would wager that the sum total of all twenty and thirty somethings that know of banksy is pretty substantial. That said, it's definitely not a household name. I'm just wondering if 98% is a great guestimate.
It's all wild speculation, though and kind of immaterial
Actually my parents sent me an email last week with links to Banksy's work :) (also, they are French, not American, so it's not a very useful test regardless)
Like most things, just getting people to talk about him will raise his profile. Being mentioned on national TV and the network news doesn't hurt either.
That said, I must confess my ignorance as I'm unaware of why Banksy is relevant. I don't mean high level ignorance, as I have googled around and I get the general idea of his works and some of the social issues his works relate to. What I mean is I'm unaware of how he became relevant in pop culture. Does anyone here know?
Banksy's wikipedia article[1] doesn't particularly spell it out. Did his first works show up in a particularly public area in response to a poignant event and the British media noticed it? Did his work catch on organically?
I suggest you just get one of his books and look at the art for a while. He's been doing his thing for a long time and has built up a following. I've been a fan for years.
Banksy is relevant because most gallery art is crap. Take that as your starting point. If you don't understand that, without having to research it, you won't get Banksy.
Banksy is not relevant to 'pop' culture, he was famous as an underground artist. Pop culture consumes anything (like the internet) that has social currency, regardless of whether or not it is relevant to pop culture per se.