I Bet This Will Work

Howdy
I recently completed redoing a site for a client (July, 2005) – the site was the usual kind of job we do. The site had been going for a year and hadn’t made any sales.
I got on well with the client and reinforced how effective the new site was going to be. I ended up saying “The new site will make 30 sales in the first 30 days or I’ll buy you a bottle of Jansz champage!”
I dropped in the champagne yesterday. The site had made 28 sales!
The client was thrilled to get the champagne (we’d been doing a countodwon for the last week) and we sat and had quite a chat.
It got me thinking at what an effective way it was to develop the relationship with the client – have some fun with them with a ‘silly’ sort of bet. It wouldn’t be the best strategy to use with a lot of clients but it was something different that kept me top of mind with this guy.
Can you do something similar?
Brendon