eBay has an outright ban on it. That is the answer, and the rest of this page deals with what that means in practice, since plenty of people do it regardless and plenty of tools are available to help them.
The policy describes this exact arrangement. eBay forbids a seller from selling items they buy from retail sites or other sources after the item has already sold on eBay. Amazon counts as a retail site, and purchasing there after your listing has sold is precisely what is being described.
Why people do it anyway
Because there is no barrier at all. No supplier to find, no agreement to negotiate, no stock to buy, no minimums. You list a product you have never owned, and if it sells you buy it. If it does not sell, you have lost the listing fee.
That is a genuinely appealing proposition, and it is why every beginner tutorial teaches this version. It is also why the results turn out the way they do.
What actually goes wrong
Your buyer opens a box with Amazon tape on it and an Amazon packing slip inside, addressed to them, from a seller they have never heard of. Some do not care. Some open a case. Some figure out they could have bought it from Amazon directly for less.
Prime returns do not work through you. When your buyer wants to send something back, you are the seller of record on eBay, and Amazon's returns process is not yours to operate.
Prices are always shifting. Amazon repricing never stops, and the margin you based your Tuesday listing on could vanish by Thursday, on an item you are still required to supply.
Stock vanishes. Amazon runs out, leaving you with an eBay order you cannot fulfil, which turns into a cancellation that hurts your seller rating.
Amazon has a perspective of its own, too. Fulfilling commercial orders at volume through a retail Prime account tends to draw attention from that side as well.
What eBay does in response
It is rarely a dramatic suspension, at least not at first. eBay's set of consequences begins with ending or cancelling listings, along with hiding or demoting all listings in search results.
That is the part that takes people by surprise. From the inside, the account appears completely normal. You are logged in, your listings are visible, and your fees are still being charged. Buyers simply stop finding you, and there is no explanation for it.
Fees you have already paid are not returned.
The permitted version
The same model, but a different source. eBay allows dropshipping when the goods come from a wholesale supplier you have an agreement with, and when you are named as the seller on the packing slips and invoices.
The real difference is that the sourcing work has to come first. Find a wholesaler, agree on terms, get your name on the paperwork, and accept that this takes weeks rather than a single afternoon. In return, you get a business that does not quietly stop working in month four.
That trade forms the whole foundation on which Ecom Accelerator runs. Before anything gets listed, its team handles the sourcing from US wholesale vendors, and the store owner is named as the seller of record. The weeks of sourcing work still take place, they simply aren't your weeks.
And what about the software?
Tools that track Amazon prices and place orders automatically do precisely what their name implies. They make the banned version quicker and more consistent, which makes the pattern simpler to detect rather than harder.
Automating something eBay prohibits isn't a way to get around the ban.
What Ecom Accelerator actually does
Ecom Accelerator creates and operates eBay stores that belong to you, sourced from US wholesale vendors with agreements signed before anything is listed and the store owner named as seller of record.
You supply the capital for inventory, while Ecom Accelerator's team takes care of product research, sourcing, listing creation, marketing and sales, order fulfilment, customer service, and packing and shipping through US facilities. Over 300 stores, plus a 250 person operations team.
You retain 70 percent of the profit while Ecom Accelerator takes 30, so it gets paid from the results. They report a 32 percent return on inventory sold between January and December 2025, and note that full growth takes twelve to fourteen months instead of arriving in the first quarter, a slower promise than any Amazon-to-eBay tutorial offers, yet a more lasting one.
The 16 month guarantee means that if you have not recovered your costs by month 16, Ecom Accelerator stops taking its share and works for free until you have. Their terms state plainly that this guarantees the service rather than your profit, that results differ, and that you can lose money.
The short version
Buying from Amazon after the sale is banned by name, and the penalty typically shows up as listings quietly disappearing from search rather than as a suspension notice.
The same model sourced from a wholesaler is permitted, and it demands weeks of sourcing work up front. Either you handle that work, or Ecom Accelerator handles it on a store you own.