@Mary Nathan While I know some have gotten calls off a mailer as few as 300, that was never my experience. I typically found that I made $100k for every 10k mailing pieces I sent. I never personally took it to the level that someone like Michael Quarles has, but I don't think no calls on 300 letters is unusual at all. While there are other experts here that can probably go deeper, here are a few things to consider:
1. Your selection - Absentee owners is one of the most popular lists. If someone(s) has already heavily canvassed the area you chose, you may be beating on a dead horse.
2. Your message - Sending the mail, and even using a yellow letter, or cut stamps, or whatever, will at best get them to read what you have to say. If you get that far, then what you say is critical for the next step - a response. When I first started mailing, I found an owner in my target list and I went an interviewed them. I also paid them for each piece of mail they received about buying their home. By doing this, I knew exactly who my competition was, and what they were saying.
3. Number of impressions - Most directly mail experts say that it takes at least 3 impressions before you build sufficient trust / name recognition for them to respond. I always mailed folks a minimum of 4 times.
There is so much more to direct mail, but you get the idea. Just as an anecdote - the first really successful direct mail investor I met made most of his money by skip tracing the returned mail, not from responses from his pieces. Technology on change of addresses and vacancies has changed since then, but a good example of thinking differently.
On our accuracy, it is really easy in most counties to go to the county and verify. We do this kind of "back testing" ourselves on a regular basis, but we encourage customers to do it too, as I'd rather they get comfortable themselves then take my word for it. Also on non-owner occupied, be sure to read the tool-tip (hover over the field with your mouse), as that explains how we determine that from public records data.
Best,
Sean