Minimum number of all users, or minimum number of users in the top brackets? Because we know we've had over 100,000 bitcoin users since Summer of 2011.
Sorry to bring up this question repeatedly:
What do we know concerning number of users (now or at any time in history)?
- Blockchain activity?
- Downloads of Bitcoin client and wallet software
- Forum accounts
- Number of users in exchanges
- Number of users in other services
- Other ways of receiving this info