Our products are widgets that are currently available on a few ecommerce platforms. They use the textual descriptions as well as the price of products to offer discounts and recommendations. One of the platforms we are on is Shopify which has an app store from which users can click an install button which then gives us access to the shop's data via an api.
A new client is using WebSphere Commerce V7 Feature Pack 5. My question is: is there anything analogous to the Shopify app store or are we better off writing an ad-hoc crawler to access the data of interest?
Slightly different. Since the integration is much tighter and you can access low level code and may impact more than just code, most companies write a white paper along with the source code (eg. Cybersource). Also IBM offers a team of developers to make sure that you're doing it correctly along with a validation program to certify the integration (IBM Business Partner Innovation Centers). Here's a list of the people who have gone through the formal program (you can create adhoc plugins, it's just that you won't get the marketing visability) - http://www-01.ibm.com/software/commerce/websphere-commerce/technology-partners/