@Brenden MitchumGreat idea on using a list /database.

I gathered my list by aggregating county databases and using APIs.

Reps from these agencies will use Airbnb and Furnished Finder to place their clients, but some of these companies have a place on their website where you can submit your property for their database. 

If you have software like Accuzip you can run your own list through the software which appends or compares your addresses with the USPS vacant database and it WILL flag the vacants for you, but you need to have the addresses to begin with. 

Jay, I couldn't seem to find you in our database, by the way...

Some companies also run TV and Radio ads.You can search real estate transactions in your tax database.

Usually the local realtors association will have a website search tool you can use and set up notifications.Craigslist will have some land deals occasionally.You can download a list of vacant land form the tax database and mail or call them.

This is frustrating being a former realtor and I always pride myself on building my database with leads.

If you can build out your database on a weekly basis maybe hire a virtual assistant to do all the research for you and you can cold call knock on doors instead of doing everything yourself

On the agent side of things, start building your database now...it can be as simple as a spreadsheet or a free one like Hubspot, but you're going to want a way to keep track of prospects, leads, and SOI (sphere of influence).