I know what works because besides the millions of pieces of mail I send for investors and agents I too use my service and I absolutely would only send out Postcards or only send out YellowLetters etc. if doing so allowed me a higher return however I know that doing so would diminish my return.

It will come down as I go, because of diminishing returns (less to save so less is saved), but I'll still end up around 100% ROI.

I wonder if people can win a judgment that includes an interest charge on the original balance due (ie. pegged to rate of inflation, etc.) so that the value of the payoff is not diminished over time. 

Diminishing returns.

Your return on equity (Net income divided by total equity) is diminishing each month with the increase in property value.

A historical downward vacancy rate suggest diminishing demand in rental in your location provided similar rental properties have somewhat downward trend.

To diminish that by inferring person C has good credit but is assumed to be fiscally irresponsible is silly. 

In fact, it diminishes all risk for collections, quite the opposite.

Unless my rental income is high enough for me to quit my full-time job, adding just another rental to increase my income by 10% (and lose 35% of that increase to taxes), is not worth the additional effort (law of diminishing returns for me).

I am a Guesty user and looking to switch away because their value prop is diminishing by the day.