@flypogger let’s say you have 20.000 running listings, and it doesn’t matter if postcards or antiques. One day, post services decide to increase shipping cost. How do you update postages for all listings without working for a month? Shipping profiles are useful for this. If you sell antiques, shipping cost mainly depends on total weight and size of the parcel. I have set a specific list with all weight ranges, something like this:
In one second I can pick the correct weight range and the shipping rate will be updated (for thousands listings at a time, without launching a revision from GS, which would take a while). My example above is not exactly created for parcel orders, I should add other postage situation like those that depends on size more than weight (like very large but light box). Moreover, I can set specific smart group to know exactly which items are using a specific profile and update them if I notice that they weight more than I expected.
Concerning the issue say by rlmartin, yes I had it too when I started with profiles, but I discovered the reason of such a bug. Any time you add a different shipping cost manually, eBay will create a new profile. If you only use profiles (for really all listings), this won’t happen again. Now I am no longer experiencing this annoying issue.