It comes down to trust. They don't know your product and they don't know you. Maybe if they meet you or engage with you on the phone they'll get to know you a

It comes down to trust. They don't know your product and they don't know you. Maybe if they meet you or engage with you on the phone they'll get to know you and gain some trust in you and therefore your product. It sucks to have to do that. Especially if the meeting boils down to showing them some example websites they could have found on your portfolio page, rather than taking four hours out of your day to visit them at their office. But it's the trust thing that gets you the job.