Shopify Collective: Supplier

I have updated my review, the concept is great and that's why I updated the review. But the work is half done. The shipping has to be figured out. I just got the order and now I am supposed to chase after the other business for shipping cost. Send invoices and such, make sure what setting they have. You can choose "calculated shipping" but it does absolutely nothing!!!! You can send invoices for the shipping cost, but if the other store doesn't reply or doesn't see your invoice, then what? You hold off on shipping and you get ding for late shipping. Also, now you need another app to send invoices or you going to have shipping as orders? That's insane