Bitcoin has limited application as a currency, hindered by technical limitations that have never been addressed to my knowledge. It can barely handle 300k transactions a day. Comparatively, Visa processes 150m transactions every day. Given that those bitcoin transactions include all the trading, while Visa's are purely purchasing, it starts to become very clear that bitcoin cannot sustain any kind of major usage as a currency. Couple that with the fact that Bitcoin's value can change so drastically on absolutely nothing, and it's difficult to have confidence in it as a means of purchasing, unless you're looking for something difficult to trace back to you.