The key is to make sure you're doing enough VOLUME (i.e. 2,000 per month) and that you repeatedly hit the list (FREQUENCY).Your expectations on your first 2 mailings should be ZERO leads.

The optimal frequency with which to send out your letters and your ROR will be something unique to your market.

On another note from the aviation world.. the Austin Center had their computers in the basement.. basement flooded  ATC went down... so you had the airlines having to resort to flying like little guys.. flying VFR patterns and calling out their postions on the common radio frequencies which is NOT very common for them.Also departures were old school once an airliner was in the que and number one for take off they had to get on their cell phones and call Houston center for their IFR clearance.. this is what happens in non radar environments.. but its a testament to our aviation system that when tech goes down we can keep flying.. albeit like its 1950 but we keep going

Beware.I suspect this is whats driving the frequency and stratospheric heights of 1st note increases. 

Next decide, what you will be mailing and the frequency.

The issue is frequency is a complete crap shoot and timing of payments is immediate.

There may be a scanner frequency that is used by your fire dept. or they may list recent fires.

What is your method/frequency for following up with these near misses?

I'm not sure about your travel, as it'd depend on the frequency and price of it.

I'm not so much interested in the number of horror stories as much as I am in the frequency (and likeliness) with which they happen.