Does the Direct Mail strategy work for Buy and Hold rental properties? what are some pros and cons to this?

Pros: It works

"cons:" It will take multiple touches to get leads. It's a long game. If you are not capitalize to do a mailing a moth for 6 moths (12 is better) then don't even start. 

I would create a strong online presence first. Now a days the first thing people do is a google search.

There are get Yellow letters companies that can automate this for you. So you go in choose which piece of mail you want shipped for each mailing and then hit "run" so you essentially spend a bit of time up front to set it up but then it's automatic for as long as you set it up for.