But bitcoin still faces challenges — some old, some new.
Bitcoin is no longer the only game in town. Other cryptocurrencies have sprung up, most notably ethereum. It expands on bitcoin's blockchain technology, allowing users not only to engage in basic transactions, but also to execute "smart contracts" that automatically enforce themselves.
Meanwhile, the law surrounding virtual currencies remains a work in process, with conflicting court rulings about how to define them.
"Are they commodities? Are they property? This is going to be a very long road for virtual currencies in general to kind of settle in to a particular legal class," Santori said.
Then of course there is the issue of crime. The value of any currency depends in part on its reputation, and in that respect the Silk Road case was a huge setback for bitcoin. But Santori says that is unfair.
"Are bitcoins used for crime? Well of course. But so are a lot of other currencies. So are a lot of other technologies," Santori said.
Many experts agree that bitcoin is actually less useful to criminals than other currencies, because contrary to popular belief, it is not anonymous. In fact, one of the IRS agents who helped to finally unravel Silk Road says it was bitcoin that ultimately led law enforcement officials to their man.
"Back then, criminals are operating under the impression that bitcoin was an untraceable currency and law enforcement wouldn't ever, maybe never, be able to figure this out," Tigran Gambaryan told "American Greed." "Well, when you fast forward it to 2014-2015, that was no longer the case."
So will bitcoin and its fellow cryptocurrencies eventually replace all the money in our wallet? Not necessarily.
Even some of the most enthusiastic boosters, like Santori, say that contrary to some of the early expectations, it is hard to beat the U.S. dollar.
"You can complain all you want about the banks, but the U.S. dollar is strong," he said. "It's a good currency. It's a good store of value. it's a good medium of exchange. It does all the things we want money to do."
But he says other countries with less stable currencies could find bitcoin to be a useful alternative — a medium of exchange for them, and a source of investment elsewhere, including in the U.S.
And as the technology develops, we may all have to expand our concept of the meaning of money.