- Coming from the same factory line with the same quality control, just rebranded (Costco famously does this a lot)
- Factory seconds, goods with very minor defects (sometimes not even in the product itself but in the box etc)
- Manufacturers copying specs and running illicit production lines without the company’s authorization
- Complete knockoffs, where the external design was copied but the product is totally different
Ultimately for most of these Amazon brands you have no idea which of these you are getting. Just because a product looks the same doesn’t mean it is the same. And in a lot of cases, e.g. with battery operated electronics the knockoff manufacturers skip a lot of safeguards and it ends up burning your house down.