If this was a "typical" chain letter asking for money or prayers or luck, you'd have my full support in tossing it out guilt-free but I think you may have a slightly different problem. This chain letter isn't so much a nuisance plea for cash from a random person, as it's a game a lot of parents play when their kids are old enough to want mail from the mailman. For the minimal investment of a handful of stickers and some stamps, they get back a few weeks of random envelopes addressed to Junior! Your SIL was probably thinking would be neat for your son to get all that mail and not really considering his age. These kinds of chain letters are supposed to be for fun but your sister-in-law has broken the cardinal rule of chain letters, which is that you NOT send them to people without their consent. Clearly, they are only fun if everyone participates, which is why you should ask your friends if they want to play before sending it along. You already know you don't want to continue so the best thing to do is either mail the letter back to your SIL with a note or give her a call and say, "Thanks for thinking of us, but we won't be able to participate in this sticker thing. I just wanted to let you know so you can ask around and find another friend to participate since we can't." You don't need to give a reason, since usually offering a reason gives the other person grounds to argue! But if you feel compelled, there are several that are true and realistic like that your son doesn't play with stickers, he's to young to understand the mailman or getting mail. If you might want to try something like that when he's older then tell her as much and suggest she call you next time before mailing it to be sure you'll be able to play along!