From a reader in the newsletter business:

Jonah: Catalog mailers (basicallly anyone sending mail third class) already pay more than the associated costs of their mailings, the excess is used to subsidize first class mailings… along the lines of how the rich pay more than their pro-rata share in taxes in order to let lower income taxpayers pass less than their pro-rata share of income. And no mailer intentionally sends you three catalogs on the same day. Mailers collect names from a variety of sources (inhouse names as well as renting names from, among other places, their competitors) and attempt to de-dupe the file to keep from sending multiple mailings to the same name. Sometimes the de-duping software works, sometimes it doesn’t work so well… and when it doesn’t, you end up with multiple pieces.

Me: Obviously this guy knows a lot more about the subject than me. But I am not entirely sold on two counts. First as Ed Capano, the former publisher of NR, used to argue about blow cards — those annoying subscription cards found in every magazine — quantity matters. The more blow cards, the more subscriptions. Ed had the numbers to prove it. I sometimes get the sense the catalog people have the same attitude, sending extra copies in the hope that one extra catalog at the margin will hit paydirt. Second, I think this is the case because if it were such a problem the catalog companies would have better software for catching dupes. If they were sending out Faberge eggs, you could be sure fewer extra were being sent out. Is it really that hard to create software that says “one copy per address”? Maybe it is. But of course I’m triply biased. I don’t like all the catalogs. I like NR and am inclined to take the side of my paymasters. And, I have the luxury of not knowing very much about 3rd class mail and the catalog business.

Update: From another reader who knows a lot more than me:

Jonah:
I have worked extensively in the mapping business (MapInfo, Keyhole, Google Earth products). Mapping software is used by the mailers, as we tend to have a lot better addresses than they do. As a matter of fact, they use our software and data sets to verify addresses…but usually not names. This guy who says they de-dup is only telling one side of the story. You are correct that better software IS available…but they’d rather send out the extra catalogs than spend the money on the software — for 2 reasons: 1) extra catalogs mean extra sales (like blow cards); 2) why spend incremental money on software that will only decrease costs when you could spend it and potentially get incremental sales?
Please tell me he won’t be your Catalog or Third-Class Mail guy.