I live in a small town (population 12,000) & I plugged it in doing 2-4-year-olds & it came up with almost 900 kiddos!!!
Like Entropy said you can buy just the list - I plugged in that I wanted 250 of those names & it said I would pay $25.00 -not bad if you want to do the postcard work on your own.
Edited to add - I know this sounds silly but one of my past clients (that I termed) is within my "mile" & I really on't want to send them a thing lol. That is one reason why I plan on buying the addresses so I can come up with something on my own to mail out & I am guessing I will know some of these families from preschool, etc. I LOVE this idea though. Thank you so much to the poster!