We converted a long-term rental in a very remote corner of our state following his training methods and the results have borne out the complete accuracy of his statement.

You can skip trace (credit bureau level data for high accuracy), text at scale, call, list stacking (to determine who on your list are the most motivated) and direct mailing with postcards etc.

Hello Joshua - Great, thank you it looks like Propstream has a good reputation for efficiency and accuracy...I think I'm going to go with it.I would love your input on my potential deal, your knowledge will be invaluable. 

@Forrest Kalk actually everything you stated for questions is known, with absolute accuracy, not via any crystal ball or guess-work but via math and data. 

Do they provide any type of guarantee on the accuracy of historical data?

You may want to keep an eye on the expenses once in a while to ensure accuracy. 

He or she will be able to answer your questions with real accuracy. 

Try testing rentometer.com and it can provide some level of crude accuracy on current market rents for that neighbourhood. 

We have been able to estimate with accuracy how much per unit (3600-3800) it costs to run a property.  

You get a cheap place, with guaranteed appreciation, and no risk - you can predict with perfect accuracy what it will sell for at any point in the future.