My team currently sends direct mail to multi-family in the greater Seattle area.
Here's a few tidbits that have helped us. There's three pillars to all direct mail marketing:
1. How motivated is your list
2. What type of mail piece you use and what you say
3. How often and what time of the year you mail to them
This may sound simple but hopefully it will give you a few ideas as you continue to send out direct mail. All three pillars work in unison and should compliment each other. For example, we once mailed to probate with a typed letter detailing how we could make selling their house easy and mailed to them right before property taxes were due. Each part of this campaign was intentional. Probate is a motivated list because a high percentage will end up selling their newly inherited property in the next year. We emphasized how little work they would need to do to the house for us to buy it because they were most likely burned out with the whole probate process. We mailed to them right before property taxes were due because this house would be top of mind at the moment they received our letter.
Be intentional with each part of your direct mail campaign. Why did you pick ownership of 15+ years as your only criteria? Why would this group be motivated to sell? What time of year would this group be more motivated? After you answer these questions, your direct mail campaign will be easy to piece together. Feel free to give me a call if you want to bounce a few ideas off of me.