I think as an overall average the for the national economy we are in the early stages of the boom.

Our economy is "slow and steady ". 

Western Md , jobs are scarce , the economy isnt that great up there .

If we are moving to a "gig economy" all those new business owners are going to need cheap space.

And let's face it our countries economy is still in trouble.

Others like weather, flight risk of contractors on projects without performance bonds, event risk from the national economy (think mortgage crisis or war with Russia), interest rate risk, etc.  

We are a boom/bust economy and if this sector of the market starts to go sour we could have a similar ripple go through the economy as we saw in 2008/09.http://dealbook.nytimes.com/2013/11/26/new-boom-in-subprime-loans-for-smaller-businesses/

Because of the already depressed economy nobody moves into the old strip center so it becomes a huge eye sore.Economic studies show that the people of Frayser still spend the money, but the percentages of people that spend dining dollars, food dollars and frivolous spending dollars outside of 38127 are staggering.  

The more units under one roof the better for obvious economies of scale.

Don't count on the seller to do your figuring, that'll make you very poor, very quickly.)The suggestions to insist upon the schedule E or the tax returns are interesting- most investors can figure out what a building needs(in terms of capex and operating expenses) and what the rents and vacancy rate should be(as those are functions of area, the economy, curb appeal, management skill, and so on,) so if I were selling a 10 unit and a buyer insisted upon my seeing any part of my tax return, I'd consider that buyer to be an irritant and I'd find one who was capable of doing their own proper due diligence.