Knocking on Doors OR Mailing?

When doing preforeclosure homes, is it better to just go up to each house and knock on the door to talk with the owner OR just mail them a letter regarding my interest in purchasing their home?

Which is a more effective procedure?

Not sure if it is an either or situation. Depending on your time frame it is probably best to have a mail introduction before showing up at their door. Your mailing should be distinctive (to get opened) and have good content that creates a good impression. You might call a few days after your mailing. I believe I would call first mailing or not. If they are bad to you on the phone I don’t think I would show up on their door step. Over the time period between the posting and the foreclosure I would do several mailings. You want motivated sellers calling you, not vice versa.