If you want people on your “team”—whatever that means to you: in business, as a partner, an employee or even just a reference thanking them more than once might be the strategy to win them over to your side as one to call upon.
It is as simple as it sounds. You simply find occasion on which to thank them more than once. Obviously, the gesture needs to be sincere to work. You’ll want to thank them for any time or resources they lend to your cause. This is essential if you want them to help you again and again. While it may sound unfair, a single thank you, while being plenty of a verbal return on their investment in you on a singular occasion, will not stick in most people’s minds. Find ways to so sincere gratitude clearly and often. You should try to go beyond words if you can. Something like flowers, a bottle of wine or some other similar gesture is a great way to go for the second or third “thank you”.
For example, if you were offered a graduate assistantship because of a recommendation from someone in your network an immediate thank you is expected and needed immediately. Very few people would find occasion to thank the person again. After you start that assistantship find a way to say thank again and give them some context about how much the assistantship has helped your career.
After a year into the assistantship, perhaps on the anniversary of its beginning, it is time for another “thank you.” Share your results with them, show this person how much you have learned and grown and thank them again for the opportunity they helped you achieve.
Now, this person in your network will have a clear memory of how appreciative you are and would likely help you again if asked. Really the message here is sincere gratitude. Everyone says “thank you” once. Demonstrate the strength of your conviction by showing this person over a period of time that you are still grateful for their service to you.