There are good people who, if they could, would choose to live in Class B neighborhoods, but they can only afford class C....that is your target resident.  

Most Class C/D areas will pencil to positive leverage, if you use generic underwriting assumptions.  

I live in San Francisco and bought a triplex in Cleveland, Ohio in a Class C neighborhood. 

Marketing material from commercial brokers in all 50 states, for all sorts of NNN, isn't useful, and you aren't going to really get insights until you narrow your focus a bit.Starbuck is a nice easy thing to watch b/c they are all over and, since Americans have largely replaced their trans fat addition (McDonalds, Burger King) with a sugary caffeine addition (Starbucks), it's likely going to do well for a few decades. 

I can show you some really good stats about it and all of the different sub markets so you know what, in general, is a class A, B, C or worse and what markets to stay away from. 

Quote from @David C.: I'm curious how CA agents can make a living with laws like AB2992 that state:"If the out-of-pocket costs to pay their agent remain too great and the seller and buyer have not yet reached an agreement on the sales price and/or terms, the buyer may walk away from the subject property provided there is an exit clause, proceed without representation, or approach the seller's agent about possible dual agency representation." 

If you apply Class A assumptions to a Class B or C purchase, your expectations won’t be met and it may be a financial disaster.If you buy/renovate a Class A property in Class D area, what quality of tenant will you get?

If the location is an A but the tenant paying higher rent was a B or a C then replacing the location with an A tenant at slightly less rent in some cases you can actually increase the value.Example if you had an (A) location QSR but tenant was Burger King franchisee and they went out the Burger King might sell at 7 cap.

Class A and B neighborhoods are above median price and C and D are below.

I don't think a mean and median would really be that helpful unless you were classifying them separately into A, B, C, and D areas, as well as similar beds and baths.