They were NOT mistaken. My own apartment complex spent $3.27 to send me a letter. There were two items in the envelope: one discussed window guards for little kids, and had to have been sent to every apartment in the place. The other was asking about my lease renewal, and was an exact duplicate of a document I had found in my mailbox the previous week (dropped there by hand, for free).
My apartment complex gave me a pain in my ass to collect this letter. I was fortunate enough to be in training last week, so I got home early and was able to pick up the letter; if that had not been the case, it would have taken a lot of finagling for me to get my hands on it. They also paid over three dollars to send me something from a building that I can SEE from my balcony (it's about . . . oh, less than 500 feet away). There a LOT of apartments in my place. Lessee, building "X" is the 24th building, times six entrances, times four doors at each entrance . . . 576 apartments, or so? That's almost $1800 they spent. My mom suggested that maybe they needed a record of people receiving the letter. Well, shit, do it by hand first, and then send it certified to the people who don't respond! No wonder my rent is so goddamned high.