> For online payments instant payments are actually not that important requirements.
When the exchange rate fluctuates as much as it does, instant payment is an important requirement.
Suppose BTC is worth $15,000 today. I want to buy a widget for $150.
I want to see 0.01 BTC deducted from my balance. The merchant wants to get paid $150.
If the transaction happens instantly, everyone is happy.
If the transaction does not happen instantly...
Let's say I transact 0.01 BTC to the payment processor. It will clear tomorrow. The merchant will get paid when it clears. Tomorrow... The payment processor has 0.01 BTC in their possession.
... Except that by then, BTC went down to $13,000. The merchant still expects to be paid $150. The payment processor has 0.01 BTC on their books, which is worth $130... and a debt of $150.
That's the problem with using BTC as a currency. You either need to pay through the nose for fast confirmation, or you expose yourself to volatility risk.
This is, incidentally, why Steam has stopped accepting Bitcoin. You can't use it as a currency. [1]
When the exchange rate fluctuates as much as it does, instant payment is an important requirement.
Suppose BTC is worth $15,000 today. I want to buy a widget for $150.
I want to see 0.01 BTC deducted from my balance. The merchant wants to get paid $150.
If the transaction happens instantly, everyone is happy.
If the transaction does not happen instantly...
Let's say I transact 0.01 BTC to the payment processor. It will clear tomorrow. The merchant will get paid when it clears. Tomorrow... The payment processor has 0.01 BTC in their possession.
... Except that by then, BTC went down to $13,000. The merchant still expects to be paid $150. The payment processor has 0.01 BTC on their books, which is worth $130... and a debt of $150.
That's the problem with using BTC as a currency. You either need to pay through the nose for fast confirmation, or you expose yourself to volatility risk.
This is, incidentally, why Steam has stopped accepting Bitcoin. You can't use it as a currency. [1]
[1] http://steamcommunity.com/games/593110/announcements/detail/...