You can instantly reply back to your opportunity right after the first dialog at the stand. This can automatically be done in an confirmation email where you can thank them for their visit at your stand, send them som brochures, send them some web pages or send them some digital files.
This email confirmation is send by simply:
1. Go to the opportunity who you want to send a confirmation email
2. Go to the 'Activities'
3. Click the Mail-icon and choose the 'Confirmation' arrow to the right
4. Select the language that you want to send it in
5. Click the Paper airplane in the top right corner in order to send the confirmation email