How to ... paying with bitcoin via coinbase?

[tammo 7]

Hello,

 

can I read somewhere, how it works to pay with bitcoin via coinbase?

Coinbase seems to be an online wallet, do I need to create an account there?

Wasn't it that way, that I have to buy a coupon there? How does it work? ...

 

Edit: If I want to make a payment and select "bitcoin via coinbase", it appears:

You need to pay within 15 minutes, otherwise the price expired.

Isn't it a bit short? A bitcoin transfer can take a few hours (I had it one time, that it needs about 12 hours!).