Congratulations, you now have a new customer. You worked hard to get this customer. Now what do you do after the sale?
Immediately send them a thank you note. In fact the moment you had that feeling this was going to be your new customer, you should have typed a thank you note, addressed and sealed it, put a stamp on it, and been ready to mail it the day you shook their hand and said “I’m glad to have you as my customer”.
Why would you write a thank you note before they have become your customer? Because 1, this gives you time to write how thankful you are feeling, and 2, gives you incentive to work harder on making them your new customer.