It might be the case that people are just tinkering with this service for fun, but the "yay, unexpected socks" use case seems like a solved problem with Amazon Subscribe and Save lists (http://www.amazon.com/Subscribe/b/?_encoding=UTF8&camp=1789&...). To each their own, but I just don't see myself reinventing the wheel with this API (not to mention paying an additional 5%) to buy socks/paper towels, when Amazon has already done that leg work for me.
I do, however, agree with meritt's sentiment above...zinc.io could be used to create some valuable services for existing businesses (rewards programs, et al), but as a user of this API, I think it'd be much more cost effective as a fixed per-order fee structure.
I do, however, agree with meritt's sentiment above...zinc.io could be used to create some valuable services for existing businesses (rewards programs, et al), but as a user of this API, I think it'd be much more cost effective as a fixed per-order fee structure.