My point was that
you can buy them online, rather than buying them in person and mailing them to people yourself.
Oh, right. I was aware of that, but I don't think it's a good idea because they charge too much for shipping. For example to ship to my postal code they're asking $6.98. If I was to simply mail the cards in a regular mail envelope (letter) it would cost maximum $1.
Also I'm not sure if they'll allow me to pay with a different address info yet ship to another.
But none of this stuff matter as it looks like there aren't many people interested in this.