Who needs to buy a certificate?
In the fullness of time, everyone. Right now it’s largely web sites buying server certificates for their SSL connections. That may undergo a huge change if desktop web site verification methods replace web server controls. That would mean that every web site would use a certificate, not just those running SSL. But the world would be a safer place. They won’t replace credit cards on the Internet (unless the credit card suppliers start issuing them as well).
