I NEVER believe a software program can find Vacant homes. Free and clear yes.
It is a lot of work but we all know the payoff is worth it.
Here is a tip I got from a friend. He goes down to his local water dept and over time made friends with the ladies who work there. (yes he is local and a seasoned investor who has lots of reasons to be in the town hall) He asked if they could produce a list of homes that were only charged the minimum water charge. Not only does he learn the homes maybe vacant but also the correct mailing address for the person paying the bill.
I don't think walking in off the street and just asking for the list will get it for you my point is real estate is local and it takes boots on the ground to find the deals. Yes we can do tons of research from home but we still need to get out there.
My opinion of these software packages is that they are directed at people who want it to be easy. The business is simple but not easy. It takes work.
My advice I would buy a list from listsource.com and do a mailing or spend it on Bandit signs or an ad in your local paper instead of sending them 995.
By the way I have fallen for a lot of the crap out there.