If you want to try putting a one cent stamp on your flier and violate federal law by opening people's mailboxes, I say go for it...they should get a real kick out of it. And you can't put it ON the mailbox either. Find a legal way to advertise!!!!!!!!!!!
8.3 Mailable Matter Without Postage in or on Mail Receptacles
[11-29-09] Whoever knowingly and willfully deposits any mailable matter (such as statements of account, circulars, sale bills, or other like matter) on which no postage is paid, in any letterbox established, approved, or accepted by the Postal Service for the receipt or delivery of mail matter on any route, with intent to avoid payment of lawful postage thereon, shall for each such offense be fined not more than $5,000.00 per individual or $10,000.00 per organization (18 USC 1725, 3571).
8.3.2 Liability for Postage
Except for limited use by newspapers under 508.3.0, any mailable matter not bearing postage found in, upon, attached to, supported by, or hung from private mail receptacles described in 508.3.0 is subject to payment of the same postage if carried by mail.
8.3.3 Full Distribution
If there is a distribution of identical pieces to all or substantially all addresses on a route, only a representative number of pieces is returned to the delivery unit. Postage is computed as described in 8.3.4.
8.3.4 Partial Distribution
If there is a distribution of pieces to some, but not all, addresses on a route, pieces are returned to the delivery unit for use in computing the postage due. First-Class Mail prices are applied to matter that would require First-Class Mail postage if mailed. For other matter, if the piece weighs less than 16 ounces, the applicable single-piece First-Class Mail or Priority Mail price based on the weight of the piece is applied, or an applicable Package Services price is applied, whichever is lower. If the piece weighs 16 ounces or more, the Package Services price is applied.
8.3.5 Known Distributor
If there is reason to believe that a private delivery firm or an individual within the Post Office delivery area is responsible for the delivery, the local postmaster notifies that party of the number of pieces and the postage due. If, within 5 days after notice, the firm or individual agrees to pay the postage due, payment is accepted and the pieces are delivered to the addressees. The party paying the postage may choose to redeliver the pieces rather than have the USPS deliver them. If the pieces are found to have been removed from receptacles improperly, they are delivered without postage charge.
8.3.6 Unknown Distributor
If the party responsible for delivery is not known or if the firm requested fails to pay the postage, the pieces are returned to the publisher or manufacturer, postage due and endorsed to show they were found in or on the addressee's mailbox without postage. If a publisher or manufacturer gives the name and telephone number of a person to contact and guarantees postage payment, the pieces are redelivered to the addressees. If the publisher or manufacturer is unknown or refuses the pieces, the matter is treated as dead mail.