For its first year, bitcoin had no price. It was traded between a handful of enthusiasts, and nobody knew what it was worth.
22 May 2010
A programmer in Florida, Laszlo Hanyecz, offered 10,000 bitcoin on a forum in exchange for two pizzas. Someone accepted, ordered two pizzas and had them delivered to Laszlo's door. The deal was worth about 41 dollars at the time.
It was the first known purchase of a physical good with bitcoin. Every year on 22 May, bitcoiners celebrate Bitcoin Pizza Day.
Why it matters
Money only becomes money when people actually exchange it for goods. Those two pizzas were the moment bitcoin went from an experiment to something with a price in the real world.
Laszlo also did something less famous but just as important: being among the first to mine bitcoin with a graphics card instead of a regular processor, the start of the race for mining power.