I tend to think that this is fairly useless, since there's absolutely no standardization to the way saddles are measured.

Going to your Specialized dealer, since they're the only ones who typically have a way to measure your sit bones, and being told that you need a certain width of saddle isn't going to help you unless you decide to buy one of their saddles. It also ignores the fact that width is only one of the many things that matters when buying a saddle. It's also important to consider the length of the saddle, the curvature, the amount of padding, etc. I'll admit that the Ass-o-meter is a great way to get people into Specialized stores but I] haven't found it to be particularly useful in purchasing a comfortable saddle from Specialized... or any other brand for that matter.

A better approach is to try to identify what you don't like about your current saddle. Is it too wide? Too narrow? Too long? Too short? Too flat? Too curved? Too soft? Too firm? Once you've decided what you don't like, you can go to a local shop and have a better idea of what to buy. Heck, take your current saddle with you so you can do side-by-side comparisons or measure it yourself and perform similar measurements on the saddles in the store. You'll still want to purchase from a store with a liberal return policy, but at least you'll have a better idea of what to buy.