The "we're all adults here" way and with graciousness. 

It is already hard enough to get applicants to pay the $40 for a single adult applicant or $80 for two adult applicants. 

By way of example, if Maryland law requires any power of attorney used in connection with a transaction involving Maryland real estate to be notarized as well as witnessed by two adults ... a Massachusetts POA that does not satisfy those requirements will likely be rejected and rightfully so.

You first screen all adults intending to live in the unit. 

I listened to a BP podcast years ago where a father paid his daughter (she is an adult now being interviewed on the podcast) to read a few basic books as her part of her summer job and I would like to do the same thing. 

However I have a family of 5 (2 adults) that pay about $120 per month. 

Any adult staying in the unit longer than that must apply, be approved, and sign the lease before they move in.

There are only 3-4 adults living in the building.

Then all adults need to undergo the credit and background check and show ID at the showing. 

They pay the website $40/per adult on the lease for this, I make nothing (which I'm fine with).If you've used up front application fees have you:1) Felt like you've lost out on potential tenants who don't want to pay the money just to potentially be denied?