tuntematon

yeah. Looks like it's configurable.

https://bitcoin.stackexchange.com/questions/12033/how-many-c...

https://bitpay.com/downloads/bitpayApi.pdf “transactionSpeed” - "medium" An invoice is considered to be "confirmed" after 1 block confirmation (~10 minutes).

I'd say it's because bitcoin transactions are not instant. To fully 'verify' that a transaction has taken place, they need 6 confirmations. The transaction may within a few seconds show up on the bitcoin blockchain, but it can't be fully trusted until it has at least 6 confirmations. Waiting for that can take some time.