在亚马逊发现有人卖我的产品，listing写着“Ships from and sold by Amazon.com”，怎么会这样？

楼主，你有把你的产品放到亚马逊上出售吗？最近有没有突然收到一些大批量的订单？

我是这么猜测的，一些供应商通过亚马逊的“Vendor Express”直接把产品卖给亚马逊：
https://vendorexpress.amazon.com/
他把发货时间设为1-2个月，这样就有充足的时间到你这边下订单，购买你的产品，然后再把货发给他的买家

楼上说到了关键点，一些卖家通过Vendor Central直接把货卖给亚马逊。感觉这已经成了一种在亚马逊出售仿冒品的新手段，最近听到好几个卖家在讨论这件事

应该是第三方卖家成了亚马逊的供应商，在转卖你的产品。你回想一下，你的产品供应链或者交易链有没有出现什么漏洞，导致产品库存泄露出去。
楼主，你去做一下test buy，最好要有产品的serial number（出厂序号）之类的东西，来证明只有你拥有这件商品

我想问一下，test buy要怎么做？这样做会不会违反亚马逊的卖家条款啊？

做test buy不会违背亚马逊的条例，它可以帮你证明其他卖家的产品是不是仿冒品、是不是从你这边拿到的。
你买到其他卖家的产品后，向亚马逊举报该卖家的违反行为，亚马逊会给你发类似这样的邮件：
“Hello,
When a detail page is created, it becomes a permanent catalog page on Amazon.com that will remain even if the creator's inventory sells out. Other sellers can list their items for sale against the page if their items match the page exactly. 
If you believe sellers are listing against detail pages that do not exactly match their items, we ask that you submit your complaint using this form: 
http://www.amazon.com/gp/help/reports/contact-us
Please include this information in your report, as applicable: 
-- Amazon.com order ID of a test buy that confirms the violation (required)
-- Brief description of the differences between the item ordered and the item received (required)
-- ASIN/ISBN of the item's detail page and the product title
-- Store or business name of the seller you are reporting
-- Other evidence that supports your complaint 
We thoroughly investigate all reports. For privacy reasons, we cannot disclose the results of our investigations, but we will take any disciplinary actions we find appropriate.
Regards,
Seller Performance Team
Amazon.com
http://www.amazon.com”

我觉得应该是其他卖家把你当成他的drop shipper（承运批发商），他手上没有产品，只能向你买产品，来完成买家的订单。他可能还有在其他平台销售产品，比如ebay。

他把发货时间设为1-2个月，这样就有充足的时间到你这边下订单，购买你的产品，然后再把货发给他的买家