Recently, Phillips announced that it will produce light bulbs with its individual MAC address. The purpose of this idea is to permit switching on and off every lamp at home (or anywhere else) by using your local WiFi net and a smartphone. I got a little bit worried, in the time of sustainable usage of natural ressources, because MAC addresses are definitely not sustainable. They are unique and bound to a single device, and ones this device is discarded (like a light bulb), its MAC address ends on the scrap yard just like the device itself.
One can do some estimations of how long will the limitted set of available MAC addresses last, until the very last one is awarded to the last Philips light bulb, of course in a big ceremony. MAC addresses are unique identifiers for devices that enable global network access. They are crucial for the increases attempts of big data collectors to unambigiously identify which computer, smartphone, tablet, or digital camera exchange information via the internet.
Each MAC address consists of 6 pairs of two hexadecimal numbers (0-9;A-F). In other words it consists of 6 byte, or 6 x 256 different strings, equally 281,474,976,710,656 possible words. This looks really like a huge number, and one might wonder if it could ever be a limitation for further growth of web. But lets just summarize how many different MAC addresses I already “consumed” since the beginning of the internet age.
At work:    5 PCs (with Ethernet cards)
4 Laptops (with Ethernet + WiFi cards)
3 ethernet/WiFi router
At home:   2 PCs (with WiFi cards)
2 Laptops with on-board WiFi + bluetooth device
1 mobile phone with bluetooth (Sony-Ericsson)
2 smarth phones with WiFi + bluetooth (HP iPaq and Samsung Galaxy)
2 handheld organizer with bluetooth (Sony Clie)
2 tablet with bluetooth and WiFi (HP Slate and Galaxy Tablet)
2 ethernet/WiFi router
3 old plug-in USB or PCMCIA WiFi sticks.
= 40 MAC addresses in total
Some of these 40 MAC addresses are already terminally out of use, together with the devices they found their way into the IT nirvana of a scrap-yard. But 24 are still in use. As compared to the > 280 trillion possible MAC addresses, this sounds msrginally. And if any other of the 11 billion people on earth would consume on average the same number of MAC addresses, 440 billions of the 281 trillions would be gone. This suggests that there is still an 500 fold excess of free MAC address available for all the future web enabled devices available, including for light bulbs, web connected fridges, kitchen ovens or electric tooth-brushes.