Frank Mischler of Mischler's Florist has written an estimated 15,000-20,000 thank you notes to customers over the past decade, earning their loyalty in an age of declining customer service.

A thank-you note got me my first real job. As a newly minted college graduate with no work experience, I was having a tough time finding my first grown-up gig. I thought I’d never get a break until I ...