[dirktheman]

Ease of use for the end users? If you have auto login enabled in your browser you can pay without even typing your password. After checkout you get redirected through Paypal, you are logged in automatically, you click 'OK' and get redirected to the 'thank you'-page. It's seamless.

Secure? That can be debated. But it is the fastest way to pay for your online purchases. I know you're coming from a different standpoint ('Why do e-commerce businesses still use Paypal?' would have been a better title in that case) but a lot of end users probably won't switch because it's easy to use.

[kruczek]

Ease of use goes a bit against security. For example in Poland there's a popular intermediary przelewy24.pl, but it is just that - an intermediary. You do not create any additional account there, instead when you make a payment they redirect you to your bank's webpage, so you need to authorize directly against your own bank. Much better IMO than having the intermediary interact with my bank all by themselves.

[dirktheman]

Ease of use and security seldom go hand in hand...