I have created a User Voice suggestion for 3dcart to offer the option to have inventory reduced on import of Amazon orders (FBS) Currently inventory is not reduced until the order is shipped, which may lead to an over-sell condition if you only have 1 or few of a particular item and it's ordered on the shopping cart before the Amazon order is processed for shipping. Here is a link if anyone is interested in seeing this option.
https://3dcart.uservoice.com/forums/...tory-reduction
https://3dcart.uservoice.com/forums/...tory-reduction