Are you pulling data from several different counties that meet your "filter" and mailing or are you only sending to one county at a time with less mail to a broader "filter"?
Example: If I am targeting parcels from 10-50 acres under $2000 market value, my available data may only be 250 parcels for 1 county. If I include several counties, Im able to send a larger mailer maybe to 5 or 6 counties that will bring my mailer up to 1500 or so.
Just wondering what your take is regarding the potency of a small data set in 1 county versus mailing to everyone in 1 county between 10-50 acres?
My 2 Cents - you really want to do two things: Apply the Law of Averages + the Law of Large Numbers.
If the average number of mailers - lets say it is 1500 to get one deal - if you mail exactly 1500 you may or may not get a deal. Even though the Law of Averages should work, you want to apply the Law of Large Numbers - mail enough "1500" mailers in order for the Law of Avergages to have a chance to work.
If you mail 6000 mailers you might not get ANY deals in the first 3000 letters, then you may get 2 deals from the next 1500 one in the next 1500... yeah, that's only 3, but the next one might be lumped in your next mailer. The DISTRIBUTION of deals are not always conveniently meted out 1 per 1500. If you use the Law of Small Numbers and send out 250 letters or even 1500-2000 letters you may get dissappointed with the results. You will not have given the Law of Averages to get a breath unless you apply the Law of Large Numbers.
If you're in the business for the longterm, mail more letters more often and you should get to the point you won't be concerned with how many counties it takes to get to a a large enough sample of mailers to get results.
Hope this helps!