I believe at latest count there are approximately 7 billion people on earth. Let's assume 1% (I know I know) use or are interested in having a bitcoin.
1% of 7 billion = 70 million people
The maximum supply ever of bitcoins is 21 million.
That means roughly 0.3 BTC available per person assuming even distribution. The numbers alone make you wonder how easily the price could skyrocket.
this 'statistic' never fails to disappoint. It's classic ignorance of wtf is really going on in the world.
Pop quiz how many people on this earth live on < $10 a day?
from 2005 puts that figure at around 80%, lets assume that nothing has changed and the richer haven't got any richer
So that 5.1 billion people who probably aren't going to be spending any of that $10 on accumulating bitcoin.
At what point does someone have enough disposable income to start saving/investing/speculating? That's the real question.
Lets assume everyone on minimum wage is investing. so say $15,000pa income. about 12.5%
of the world earn that or more. That would put you viable candidates for bitcoin at 875m rather than 7b. Quite a difference.
I would go so far as to say that $15k isn't really enough. You are probably going to need to be earning twice that which makes your sample about 500m. That's more like 4 BTC a person, its still not a lot, but at least its a bit more realistic than 1% of *everyone*.
Now to play devils advocate...
So lets assume that each of the people invested only have 1% of their total NW invested. Given that these people own most of the money in the world between them. Assume 800billion (real) dollars exist, so 8bn of that in bitcoin gives us ~$380 a coin.
If BTC was to replace 1% of the $40 trillion
well thats more like $19,000 per BTC.
Right now though there is huge, and incalculable risk that the whole marketplace could become worthless overnight, so maybe $6 is about right. Who knows.