I was under the impression that items "Sold and shipped by Amazon" were actually purchased by Amazon as well, which would imply quality control (for example, I

I was under the impression that items "Sold and shipped by Amazon" were actually purchased by Amazon as well, which would imply quality control (for example, I don't expect Amazon to buy Apple products from anyone other than Apple). I don't think that's an unreasonable expectation, yet I learned from this thread that it's not the case.