Here are the average response rates we have seen based on our customer feedback as well as our own mailings throughout the years: Yellow Letters- average response rate of 8%-9%, all kinds of calls (angry calls, curious calls, tire-kickers, quality calls)Typed Letters- average response rate of 8%-9%, all kinds of calls (angry calls, curious calls, tire-kickers, quality calls)Postcards- average response rate of .5%, mostly quality calls.Zip Letters- average response rate of 2%, mostly quality calls.

I'm going to chime on the "good property management" piece of this thread as I think it's the most relevant & hopefully helpful.  

@Joe Splitrock  depends on the area and the customs..I remember my first venture into a new subdivision in Charlotte and was staggered that you had all these new houses with driveways leading up to the front of the house but NO garage  LOL.and I Charleston were we are building parking is defiantly has value.. some lots that you can only park on are worth north of 100k for a small couple thousand sq ft. 

EXAMPLE: In my area if you do an inspection you  then have to provide the relevant pages of the report within X days.

While generic project mgmt products can be twisted and customized to do what you need, they do not understand/ account for the specific requirements of our industry.

I interviewed 3 different managers for ~30 minutes each (my own custom questionnaire is available if anyone wants a place to start with finding a PM).

I asked this question in a separate post, but figured that would be not relevant to the original question, hence reposting here - What are some of the methods to determine a neighborhood class (A, B, etc)?

They have very quick customer service responses through email as well, i was initially concerned since that's the only way to contact them but its been fine.

I just happened to mention it here because it was relevant. 

Some can create a custom surround with a window but haven't looked into this.