Kraken does not have a direct to Coinbase or any other exchange. In order to buy BTC using your bank account, you will either need to use a 3rd party company such as Coinbase or Bitstamp, transfer money from your USD bank account into the country you want to deposit temporarily, and then immediately withdraw tokens back into their respective cryptocurrency exchanges. The cost of this process is much greater than if you paid with a credit card.
Another very popular option is Kraken’s Direct To Exchange System (D2X), which allows you to make deposits directly into the corresponding currency on the secondary market (where bitcoin is purchased by fiat). This method of payment can take anywhere between one day and two weeks for funds sent through D2X to show up on your account or on another cryptocurrency platform.
How do I know if I should be buying Bitcoin rather than Ethereum?
While Ethereum has more applications today (and thus more real-world value) than Bitcoin does at this point in time, it is still worth noting that both networks are relative equals relative to rapidly changing technological developments that could alter their positioning throughout 2018 and beyond. Indeed, it wouldn’t be surprising if Ethereum showed mass adoption before Bitcoin has fully adopted its latest version 0x v2 standard due out some time next year – even though for now appears slightly lagged behind.