The most common objection I hear to direct mail is demographic: "my customers are young, they live on their phones." It sounds airtight. It is also, according to the research, close to backwards. The generations that grew up with full inboxes treat a full mailbox differently than their parents did.
What the USPS research actually found
USPS research on millennials reports that 62% say they read the advertising mail they receive rather than tossing it, 62% had visited a store in the past month because of something that came in the mail, and 47% visited a brand's website after receiving a mail piece, the highest of any age group. Large majorities also describe print ads as more trustworthy than digital ones.
Gen Z surprised researchers even more. The USPS OIG's Generation Z white paper found that the youngest cohort perceives mail as meaningful, with more Gen Z respondents associating happiness with mail than with digital communications. When every brand you have ever bought shoes from emails you daily, a physical envelope with your name on it reads as effort.
Scarcity did the marketing for us
My theory, and the data supports it, is simple scarcity. A millennial receives hundreds of digital messages a day and a handful of mail pieces a week. Attention flows to the empty channel. The Household Diary Study, which has tracked American mail behavior since 1987, shows household ad mail volumes that leave plenty of room for an individual piece to stand out, a claim no one has made about an inbox since 2009.
The tactical takeaway
Do not exclude younger zip codes and renter-heavy neighborhoods from your mailings out of instinct. Test them, and let response data make the call. Younger recipients are also the easiest to convert from mail to digital action: they scan QR codes without hesitation, which means per-recipient tracked codes measure this audience beautifully. In our world the question is never "do they read mail," it is "which streets scanned," and the answer frequently skews younger than clients expect.