if someone sends you a thank you letter for some work you did....

[helsi]

can you use a quote & their name from that in your marketing material or do you have to pay them to use their name?

Don't think you necessarily have to pay them, but I think it would definitely be wise to ask their permission.

Yes I thought that JackieNo. Thinking about it you wouldn't pay them as you couldn't guarantee it was a genuine quote could you. Some people would say anything for money!

Yes - true! Good to have something in writing saying they're happy for you to use it in publicity, though.