[Your letterhead, if desired; if not, your return address]
[Date of lettermonth, day, and year]
[Recipient's first and last names]
[Street or P.O. box address]
[City, State ZIP code]
Dear [recipient's name]:
It was great to talk with you this week. Thank you so much for providing me with names and contact information for several client leads for my business. I will be sure to get in touch with all of these people and will let you know how things progress, as I work to secure projects with these new contacts.
The leads you have provided have much potential, and I thank you again for helping me in this valuable way.
[Sender's first and last names]