i use only bitcoins for online shopping
that is the reason why they ask you for what you would use for online shops. And i think you are making a big mistake ok bitcoins are nice to pay with but paypal will give money back if you dont receive anything so wont bitcoin...
That is why escrow services exist for this kind of problem in bitcoins. If a certain condition is not yet met, then there is no transaction or it is halted. This was a pretty common problem that is why it is addressed easily. The problem now is that many people still prefer to not use escrow because it takes extra effort and payment to do so with the risk of a scam transaction.