Back in the days when there was Bitcoin and just Satoshi testing it, how did other early adopters of bitcoins came to know about it? Did he advertise about btc somewhere to attract people's attention to this new technology? How did bitcoin users initially rose from zero to millions ?
He asked advice and testers on message boards and eventually bitcointalk sprung up out of that. I think when it really hit off was when mtgox started trading bitcoin, and more when a pizza got traded for 10000 bitcoins.
Some groups and websites started accepting bitcoin at the start, like wikileaks which started accepting bitcoin as donations, there is also the infamous silk road deepweb site that sold all kinds of drugs and started accepting bitcoins. A lot of other criminals and criminal organizations started using it until today, a big part of bitcoin success is definitely thanks to criminals and even terrorists.
I'm pretty sure that was after the bitcoin pizza and after mtgox started up though.