I too, love them referrals! I have one customer who is responsible for probably $4000 worth of work the past three years, and another to the tune of about $3000. I send a $20 Applebees gift certificate along with a letter for any referral I get from any customer. It's the cheapest form of advertising there is! I actually dropped my newspaper ad July 1 last year, and stayed busy through October thanks to this type of customer. Saved about $1200 in ad expense too!
I'd love to get new construction decks around here, but everyone here thinks you have to wait a year, then they put some Thompsons crap on it themselves (at least the first time).