Interesting. It is worth noticing that MtGox had a million users and losses were somewhere between half a billion and one billion dollars.

That means we should already be at a few million users since not all users had MtGox accounts. Those who did stored on average $500 there, mostly in Bitcoins. But how large part of their holdings did the average user put in? (And how average were MtGox's users, really?)

These numbers should at least put is in the right ballpark. I am a bit surprised that we are this far ahead really. That the valuation of Bitcoin is in its future promises, and not in today's economy, should not come as a surprise to anybody, but I think your heatmap shows that we are not really that overvalued. Especially not considering what dot-com companies are worth, and Bitcoin is not just a company but a whole potential economy, should it work out.

I do however think that your axis are skewed. Should Bitcoins become widely used, I think the average worth per user should be expected to drop (since its value as an investment lessens) but the number of users should be expected to be at least an order of magnitude larger than twelve million. Facebook alone has over a billion users. Two and a half billion use email. How many users wants the ability to pay someone effortlessly over the Internet?