I got some of these as a freebie in the mail the other day. I have to tell you that they are among my favorite office supplies. I don’t use them much for regular mail like greeting cards and such, because I don’t do much snail mail corresponding. What I find them great for is labeling my stuff: dishes I take to pot-lucks, knitting books I lend out, and such as this. I went through about 50 of those in one day once, lending some patterns to a friend who had been burned out. The return address labels made it easy for her to sort my stuff from hers when it was time for them to come home.