I know it'd be terrible network practice and terrible standards-wise and just generally terrible, just figured I'd double-check before buying a crate of Tide buttons and discovering they all report the same MAC
According to a stack exchange discussion [1] duplicate MAC addresses could result from spoofing, a mistake during manufacturing, or willful negligence on the part of the manufacturer. I'd expect Amazon to follow the standards.
[1] http://serverfault.com/questions/462178/duplicate-mac-addres...
My fear was that they'd pick 1 MAC and declare "this shall be the MAC of Tide buttons", increment that 1 for Bounty buttons, etc etc
For example, there are apartment buildings that provide WiFi for their residents. If two residents buy the same button, chaos would ensue if the two buttons had the same MAC address. For the personal care stuff, merely having multiple people using multiple bathrooms who all want magic buttons to order more would do it.
It sounds like the button only connects to the network when it needs to (which makes sense to preserve power) so you could get away with it much of the time, but if two people hit their duplicate buttons simultaneously you'd have trouble.