For Yahoo stores, this is an amazing app- I used it with great success at Yahoo and was excited it was available here. Unfortunately, it is not sufficiently integrated into Shopify in a way that was workable for me. Even then, it is a great program and from the other reviews it is a godsend in addressing the limitations of the Shopify shipping features. The issues here are integration with Shopify and needless antagonism from a member of the KW team (not Burt).
As you can see from all of the screen shots even in the app store, ASM is still very much a Yahoo product. All of the program documentation is for Yahoo and there is no direct Shopify integration. In Yahoo, you can make edits on the product page, but in shopify, setup and edits are done via CSV file.
I asked about paying to have them do the setup, but that was not an option.
As for customer service- yikes!
Burt is great- I have worked with him previously and he is pretty much perfect- easy going, knowledgable and responsive.
Unfortunately, Dan from their team is strangely inappropriate and antagonistic so be prepared for a flurry of unpleasant emails if you find this program does not suit your current needs as a Shopify merchant.