How to Start a 9x12 Shared Mailer Business: The Full Workflow
Five phases, one card, and a repeatable calendar. This is the operating system behind a shared mailer business.
August 21, 2026
A 9x12 shared mailer business is simple to describe and detailed to run. You sell ad spots on one oversized postcard to non-competing local businesses, then mail that card to every home on a set of USPS carrier routes. The businesses split a mailing cost none of them could justify alone, and you keep the spread.
Phase one: plan the territory
Pick a mailing area your advertisers actually serve and build it to a clean home count. This determines your postage, your print quantity, and every number on your rate card. See the full walkthrough in our route planning guide.
Phase two: build the advertiser list
Work from categories with high customer value and a local service radius. Sell one business per category so exclusivity is real. Details are in how to find advertisers.
Phase three: sell the spots
Your rate card should show spot sizes, prices, the home count, and the mail date. Sell the anchor spots first, then use those names as proof when filling the rest. Collect payment up front or half up front with the balance at proof approval.
Phase four: design and proof the card
Set the design standard, produce ads to the grid, and lock revisions at two rounds. Layout rules are covered in the 9x12 ad design guide.
Phase five: track, print, and mail
Assign a unique QR code to every advertiser before the card goes to print, per QR code tracking. Then bundle by route, generate facing slips, and drop at the accepting post office, as described in the facing slips guide.
The economics in plain numbers
Your costs are print, postage, and design time. EDDM postage is a per-piece rate well under a first-class stamp, and 9x12 printing gets cheap at volume. Your revenue is the sum of the spots sold. Operators typically target a card that is profitable at roughly 60 percent sold, which means every spot after that is margin.
Build a mailing calendar
The business compounds when the same territory mails on a schedule. Four to six mailings a year means advertisers renew instead of being resold from scratch, and your route plan, ad files, and slips are reused each cycle.
Tooling
Each phase above has one job to automate. EDDM Tools bundles all five tools for $40 per month, which is less than any two of them cost separately.