Hi guys!
We got a solution that will allow you to easily keep your inventories sync between Shopify and your others market places like Amazon, Magento, eBay.
At the moment we just got Amazon integration in a beta state but we are working on Magento and eBay, mention that this will be a bidirectional sync so does not matter where do you like to upload your products more they will be in all places.
Check us out at: shamzify.me
Hope you enjoy our product and it make your life easier.
Thanks,
Follow us on Twitter @shamzify
Shamzify Team