A New Dimension in Weight
However, that doesn't mean there isn't some homework to be done. And those who are using a mail service such as Endicia are fortunate to have dedicated staff doing it for them. "It will be seamless in terms of software," said Moskyok, "but it's a good idea to familiarize yourself with the new system because it is complex. One big new concept relates to 'dimensional size,' or how much space a package takes up, not just how much it weighs."

• Priority Mail now has a dimensional weight for parcels that are over 1 cubic foot in volume and shipped to zones 5-8 (over 600 miles). Except for oversize parcels, the rate change for most low-weight packages shipped to zones 5-8 is in the range of 13-24 percent, whereas those shipped to zones 1-4 increase much less and in some cases decrease.
  
• Parcels addressed for delivery in Zones 5-8 that measure more than 1 cubic foot in volume will be charged the higher of their actual weight and a dimensional weight. Computing the dimensional weight takes some work: The dimensional weight is the volume of the parcel divided by 194 and rounded up. For a box, you measure the length, width and height and multiply them. If it exceeds 1,728 cubic inches, you divide the result by 194 to determine the dimensional weight in pounds.
  
• First-Class Mail is now rated based on whether it is a letter, flat, or a parcel; with parcels being the most expensive, and lower weights increasing more than higher weights. For letters and flats, higher weight postal rates actually decrease.
  
• Media Mail rates are increasing by up to 33 percent; with the steepest increases in the low-weight packages. Rates for higher weight parcels actually decrease.
  
• The old eight classes of International Mail will be consolidated into four classes aligned with the domestic classes: Global Express Guaranteed, Express Mail International, Priority Mail International and First Class Mail International.
  
• The USPS-provided packaging for Priority Mail and Express Mail, including flat rate envelopes and boxes, will also be used for the International version of these classes.

Media Mail, Cargo Shipping Take Hits
So, how does this all translate to the cost of doing business? With most fees going up, many online sellers are alarmed. In fact, one eBayer wrote in a forum: "I just came home from the post office, mailing off my latest set of videos that I sold and decided to check for the increases in Media Mail coming. I just about fell out of my chair! Yikes! I am thinking I will have to increase my shipping charges by .79 to 1.00 to cover the additional expenses. Because I sell items at a very low cost, and cater to that buyer, this will have a huge impact on my business."

Small online sellers of rare or obscure items who rely on foreign markets, such as specialty booksellers, are also going to feel the pinch of the new rate changes, as the Postal Service is no longer shipping individuals' parcels on cargo ships, called "surface-transported economy service."

In an eBay USPS International discussion forum, a representative outlined the following restructuring: "The USPS is eliminating surface-transported economy services. The USPS has experienced continuing volume decline for these economy services. Economy services that use surface transportation account for only 2.7 percent of total international volume. As a result, efficient international surface delivery networks have diminished and costs have dramatically increased."

Sellers who used "surface deliveries" for foreign buyers will sorely miss the service because the cost is about one-third of air mail.

Packaging Primer
Still, there are things you can do to keep shipping costs from eating up your profits. With the new size versus weight paradigm, you may be able to save money by changing your packaging as opposed to focusing solely on keeping the weight down.

• For Priority Mail boxes, consider changing packaging to stay under one cubic foot.
  
• Take some time to measure your current supply of shipping boxes. If any of them are over a cubic foot, do they need to be? Could you safely ship your items in smaller boxes?
  
• It's a good time to get in touch with your packaging supplier and see if there are other workable options for padding and packing your parcels. Also, look into using variable-depth packaging so you can always fit the container as closely as possible to the contents.
  
• For First Class mail, think about folding the contents to make a flat-sized mailer over into a letter-sized mailer.
  
• Use USPS free packaging. If you use any of the U.S. Postal Service's wide variety of free packaging options, you don't have to worry about it meeting their requirements for shape-based pricing.
  
• Use Stealth Postage for International Shipping. (Stealth postage is the practice of printing shipping labels with postage amounts hidden from the customer so you can charge a different fee for shipping and handling than you pay for postage, allowing you to average out your costs across a product line or to cover costs associated with packing such as labor and materials). All of the new international shipping classes come with discounted online rates when using stealth postage.
  
• Use flat-rate options, including those for international. Flat rate envelopes and boxes are the same price no matter what the weight. Visit this USPS page to see what options are available. You may be able to save on smaller heavier packages such as books. Keep in mind that there are weight limits for some of the new international flat rates. Weight limits vary for different classes and sizes so make sure you know if there is a limit for what you're using.