Other than rent, what income streams do you get from your tenants

[Josh Caldwell]

I make money from my tenants as many ways as possible. 

I have coin op laundry in the units

I make money on credit repair for tenants.

I make money on the utility bill for my tenants.  This one is my favorite. 

I have some tenants who do rehab work for me in exchange for discounted rent that is much less of a discount than it would cost me to hire a handyman.  

What other profit centers am I missing?