On FOR SALE property, we only publish listings from MLS' and from a few select new home builders. 

That is what I did with the consulting business, the software publisher I still own and oversee (notice I did not say "run") and my investments of which real estate is a part.

Use Cozy.co for publishing ad out to the rental sites as well as credit & background check.

I publish my prequalification standards in the listing. 

Thanks @Tom Sharkey,We don't publish for that one as much as my Creating Wealth show because we're a little worried about oversupply in the STR market.

Zillow is a for-profit enterprise that knowingly publishes incorrect information.

This is not exactly a total data population that I can derive any industry publishable stats.

PSU publishes a quarterly report on the Portland area real estate market that includes a section on multifamily.Because Great Falls is a relatively small market finding a commercial provider of apartment data with great coverage is probably unlikely but you could check with Axiometrics who include Great Falls on their list of markets covered.

(Our sheriff's department publishes an on-line map.)If yes, I would adjust my offer price accordingly.  

Eventually, these rules will published, so I recommend you to be ahead of the game.