How does m2e pro "Reserve QTY" work?

Question

The m2e Pro extension now has a "Reserve QTY" option that seems to be used to better handle out of stock conditions... but for the life of me I cannot figure out how it is supposed to work.

Here is the doc link and the "help" copy:

You should use this option to prevent the item being sold, before Magento Order created (as the Product Stock QTY only reduces after Magento Order creation). It removes items from Magento Stock at once eBay Order comes from eBay. Reserve qty will be used when Magento Order is created or released when the term of qty reservation has expired. Orders-ReserveQTY

I read this to say,

"You should use this option to prevent an item in your Magento store from being sold after Amazon or eBay sells your last one, and before the Magento order for that sale is created. Magento store inventory only updates after the Magento order is created; there is a delay between the sale and the order creation. So, this option reduces the relevant Magento store inventory immediately when the Amazon / eBay sale comes in from the marketplace... then there is some bit about reserve quantity which I totally cannot understand.

I mean... in what case would it ever take m2e longer than like 15 minutes to create that order? Right? 15 days? Where does that come from? Shouldn't the options be more like 5min / 10min / 15min / etc?

Answer 1

OK, as per the comment by Zyava, the text in the M2E manual (hint, M2E manual writer: copy this text) should read:

Reserve QTY:

This option reduces the Magento store item inventory immediately when the Amazon / eBay sale occurs in the marketplace and creates a "reserve" inventory that will be used when the Magento order is created upon payment. If the order does not complete (receive payment) within your "reserve period" then the order is canceled and the inventory is put back into the Magento store.

Why? The time between an eBay or Amazon purchase and the payment for that purchase can create inventory issues. To remedy this, use this option to prevent an item in your Magento store from being sold after Amazon or eBay sells your last one (ie: before the Magento order for that sale is created upon payment).

Answer 2

It will always reserve this QTY incase of issues with syncing.

Example: You have 12 widgets and create an automation rule that post 4 on eBay and 4 on Amazon and you had a reserve rule that kept 4 widgets behind.

What could happen?

...Well lets say on Day 1 you sold 4 widgets on ebay AND 4 widgets on Amazon but the transaction took 5 days to clear to "Completed" status (on amazon) and your M2E pro settings could have been set to only reduce quantity on "Completed" status, not "Pending".

If eBay automation rules synced daily, then those 4 that sold on Amazon would still be considered inventory and eBay might re-list 4 that you really don't know if you'll have because you're waiting on Amazon to clear the transaction.

Let's say it does clear on Amazon ...and eBay relist sold some of those 4, you wouldn't have a backorder.

Reserve QTY keeps an amount around for "errors" in inventory sync situations where your automation rules are created to aggressively post items down multiple channels with as much QTY as possible.