I couldn't do it with out them or you. I almost always am contacted by people who notice a car, and then sometime later see some of my advertising and are reminded of it. It is extremely rare to have someone who has seen one of my ads first. Because they didn't think at the time that they might be looking at a stolen car, they typically don't get a lot of details. It is often weeks or months between when they see a car and when they contact me.
Memories can fade with time.
Another big problem I have is that people, bless their hearts, really want to believe they found my car. There is a yellow '69 GTX about 30 miles from me which does not have a black vinyl top. I have had at least three or four people see that car, and call me sometime later swearing it had a black vinyl top like my car. This is just an annoying part of how human memory works. Memories can grow with time.