In fact, they never collected any past due rents!

And we work to achieve our position collectively. 

@Michael Randle Essentially ground rent is an antiquated system whereby one person (or entity) owns the right to collect ground rent fees.

You can start by looking at the city's page, Best Places and City Data to get you started.

If I give a free month as incentive I am guaranteed the lose of $3500, if I take the gamble and not collect the deposit, I’m hedging my bet that the tenant wont trash the place, and therefore less likely to lose $3500 bucks. 

Instead what usually happens is the owner pays for it upfront and then collects what they can over time until paid off.That is if as already mentioned an owner did not already account for it with so much reserves per sq ft while owning to properly maintain the asset to a high standard.When buying a retail center the first question I ask is about roof and parking lot because they tend to be the most expensive costs.

I want to thank the collective wisdom of bigger pockets community that enabled me to grow from 13 doors to 75 doors in 2 years while also holding a full time job in technology (I own and self manage these properties with a 50% partner).

Also Megan's data base....

They collect the offers and break them down for the seller based on a number of factors (purchase price, financing and/or proof of funds, deposit, contract contingencies, closing date, etc). 

In 2 years time it went up $90K and would have collected  $45,600 in rent for a total of $135,600 profit.