>In order to find potential customers which is better : In person or by phone
>
>My gut feeling tells me that nothing beats the "in person" approach. But just in case is there an occasion where approach by phone would be better?

nowadays so many people bug us by phone that people do not pay much attention to phonecalls. They ignore them as SPAM.
In person communication is better way, but if you can get right time when pottential customers can place enough time for the meeting and demonstration. We ussualy make some demonstartion and give them a CD with demo. Usually customers return to our conversation when they strike some problem with their existing softare.

>Let me give you examples of probable approach.
>
>First approach : Better in person.
>Other approaches (in case first approach potential customer was not interested): Always preferable in person?
>
>How long should we wait before contacting again a potential customer that was'nt interested the first time we visited them?

when customer contact person changes. If one person do not like your software and feel comfortable with used one you couldn't force him/her to switch. But if in this place appears new guy, it is open for suggestions and it easy to show him advantages of your software.