I think the new dimensional structure is the worst mistake in postal history. Nobody will be able to figure out. It will lead to mass frustration and confusion. And they think it's the greatest invention since the spoon. What's worse, USPS doesn't make its requirements clear. They make the requirements available (barely, in some cases). But available and clear are two different things. I for one can see that I'm not going to get any answers to my questions. I've tried. I've dug through the DMM and mined the USPS site for info and nothing is explained. The standards are scattered all over the site. They are simply saying we now have a dimensional standard and it's up to you to stumble upon the requirements. Like I said, the information is there. It's just not easy to grasp. I'm a Trading Assistant on eBay with some pretty substantial experience in shipping. In some cases, I'm more on top of things than the local post office. I'm confident I will be able to figure this new system out in the long run, but I feel even more sorry for the average customer who has no shipping experience and is in for a giant headache. USPS should have a dedicated guide to help people understand the new system. But they don't. Making a good and successful product more complicated and confusing is the biggest step backward a company can possibly take. They have an 11-step process for figuring out dim. weight--11 steps!!!!!! They've got you dividing and multiplying sizes. Since when did mailing a package require a degree in advanced math? That's an exaggeration. But I'd slam USPS with a big negative feedback for this one. This new system is completely unnecessary for the customer.
Now, here is my advice for anyone struggling with this and selling on eBay. 1) Always use calculated shipping so eBay does most of the work for you. 2) For USPS supplied boxes, never worry about size. 3) For any non-USPS supplied boxes, always measure the dimensions, and enter them into the dimension fields when setting up your shipping auctions. 4) eBay will calculate everything for you; no worrying about zones. 5) If you have a package that you know is non-machinable, select the "irregular package" box. 6) Always use free carrier pickup when applicable. At the very worst, USPS will return your package to you and you'll have to take some steps to make sure it is ready to send.