--snip--
Nice article and congratulation for discovering merchant which accept
zero-confirmation 
Also, almost-instant transaction confirmation aka
zero-confirmation already used/accepted since few years ago even without SegWit.
It's not the merchant doing this.
It was Coinbase because he/she had already an verified account with them.
Of course i know that, but what i mean is the merchant accept
zero-confirmation because they use Coinbase (or other payment processor/gateway which let merchant accept
zero-confirmation).
Yeah, you put the emphasis on the merchant, I did on the payment processor.
In the end it's indeed the same result as they are collaborating for this.
maybe this is an opportunity for someone to set up an online payment company that works exactly as PayPal however they use cryptocurrencies rather than fiat.This is bitcoins creating a number of employment and entrepreneurial opportunities.
You're 6 years too late, we already have one and it's called Bitpay.
And what Coinbase is doing with its wallet is basically the same.
It definitely has become faster than earlier. But sometimes, I feel why to use bitcoins to buy stuff. It is better to keep it with you and HODL.
If we all would HODL, nobody would create services accepting bitcoin because nobody is spending
BTC.
So nobody will use
BTC and it's value will be, guess what, the same as the usage. 0