I think that you don't need to improve this behaviour. You can just use an other mean such as:
1. posting ads on free ad websites and by facebook
2. distributing prospectives (in that case you don't need to make a presentation to people face to face; you just have to give answer to their questions may be by phone when they will call you).
It is always very difficult to change a behaviour, so it is better to reach your goal by other means.
