Recently, USPS announced plans to slash the number of mail processing centers it operates in half, leaving small business owners to revamp how they time their direct marketing initiatives.

In the continental US, first class mail is currently delivered within one to three days. However, with the closing of some processing centers, this could increase slightly to two to three days.

One way small business owners can save money on postage is by reviewing their mailing lists. Owners can use address validation software to ensure customers are still at the same residences, while updating their list of actual customers.

"For instance, sending a mailing to everyone who lives in your shop's zip code is less effective - and more expensive - than sending an invite to shop or discount offer to your actual customers," Entrepreneur magazine suggests. "You'll want to cater to your best customers, not everyone in the neighborhood. Also, if you receive returned mail, be sure to cross that person off your list."