If I know that someone
wanted to list or sell a home, I go to meet them in person. I would not write them a letter. I may follow up my visit to them with a letter.
Letters are for prospecting and getting your name out there. If you know someone is ready to list, then go get the listing!
If it's an unrepresented seller (FSBO) then I put them on my targeted mail list and send them some helpful information* on a weekly basis. I usually call or visit them after the second week.
Scott
*I'll be happy to share my system with you, just send me an e-mail.