It could be the location, i.e. coastal SoCal (or conversely at the airport where people are literally trapped for hours), it could be the exclusive presence of unique brands or merchandise (think boutique/trendy/artsy), something special has to draw traffic.

We've had double digit value increases the last couple years and the trend looks like it will continue, albeit at a slower clip.  

The markets tend to be suburban to rural versus urban core and are hard to finance except the local banks who have a branch presence there.

In this case all they do is dig it up at the street and run a new plastic line through the old line.

Strong property management presence in place.

From what I understand 1-2 months of supply = Double digit appreciation

Other side of that coin is you can become a passive investor and become the bank and loan tour money out and make double digit return on that money.  

A lot of states nowadays have Meghan's Law where the whole community will be notified of a presence of a sex offender and also restrictions on where such a person may live (not within so and so distance of a school, church etc). 

How do you handle on-site presence?

On the North side the common investment approach is to accept low single digit cap rates in order to get price appreciation.