Generate Revenue From Referrals

Referral business is the best form of marketing. It is also the easiest. 
However, generating a good number of referrals requires you to have the right system in place. 
Customers are more likely to refer your business if they are rewarded. A promo code for a future tour, or a free gift, can help persuade them. 
Send them a reminder email a few days after the tour. Don’t do this straight away as they are probably still on vacation and will forget about your email if sent too soon. 
Most businesses don’t have a proper system in place and if they did, would easily generate more sales.