The next time you buy a PopSockets cellphone grip from Amazon, be forewarned: It likely won’t come with a manufacturer’s warranty — because it won’t be coming from PopSockets or one of its authorized sellers. That’s one of the trickle-down effects of a power move that Amazon recently made against PopSockets and other brands that sell their goods through the largest online store in the U.S. Amazon is taking more control over where and how product manufacturers can hawk their wares on Amazon. It wasn’t always this way for PopSockets. For several years, the company saw Amazon as an integral part of its business. The startup, which makes popular circular contraptions that can be used as a grip or a stand affixed to cellphones, sold its accessories at wholesale prices to Amazon, which then sold them at retail prices to Amazon.com shoppers. Read more at Recode.