I though monoprice just sells out - of - tolerance factory seconds, and covers the high failure rate which a free-replacement. The MicroUSB cables I got from them were junk.
While I'm leery of buying anything that requires a lot of "engineering" or "design" from them, I've been quite happy with the cables and simple accessories like memory card readers I've gotten from them. I've been studying cables and connectors for a long time, and have had loads of my own custom cables and connectors manufactured in China. While I haven't done an analysis on the connectors they use, I recognize that their cables are made from high quality cable stock - usually from Copartner, which I regard very highly and believe to be the top shelf of the cable stock that you can get from China. Their mains power cables are very nice too, and they stock enough variants that my spec is usually met from their stock (for instance, 14 or 16AWG, right angles, 10 feet) without having to special order.
I even have Monoprice supply some of the commodity accessory cables that I include in various bits of kit that I sell, such as plain serial cables. I thought it would reflect badly on me when they started molding their name into the cable ends, but so far it seems that nobody's been unhappy.
No they actual manufacturer a lot of what they sell. You should listen to the NPR Planet Money episode it was really enlightening. I starting buying from them after I heard it. I also just thought they bought and sold sub par parts.
The MicroUSB cables I get from them are fine, they just stop working after about a year. I stock up occasionally because I can buy a ton of them for cheap. But a friend of mine showed me these http://smile.amazon.com/Salsar-Colorful-Braided-Charger-Sams... and she says they haven't given her any trouble.
I even have Monoprice supply some of the commodity accessory cables that I include in various bits of kit that I sell, such as plain serial cables. I thought it would reflect badly on me when they started molding their name into the cable ends, but so far it seems that nobody's been unhappy.