I could give you 0.18 BTC for $50 paypal.
You will go first and wait for 10 days.
OR
I will send to escrow and you will pay me and wait for 10 days.
I will not wait 10 days for my btc unless you have a long list of vouchers saying they got what they paid for.
If you have another payment option which would be irreversible on my part, that can be used through escrow and does not require a 10 day wait, I am all ears.