A lot of people selling software on eBay cheaply are mentioning in their description "in keeping with eBay's policy a piece of non-connected hardware will be supplied with this OEM software".  Immediately, let me tell you, this is illegal. OEM software (it stands for Original Equipment Manufacturer) is software provided either pre-installed into a computer system by a factory / supplier or software provided as a courtesy with a specific hardware device.
Some good examples are Nero Burning ROM being provided with some DVD / CD Burners. This is an OEM version which is provided with a burner, albeit not a full featured version but it carries out the job in hand. That is exactly the case. Why supply a piece of non-connected hardware? If you wish to buy Nero Burning ROM OEM version, why would you want, for example, a modem to be supplied? This is exactly what the advert is stating.
If you see someone selling OEM software, it is illegal. OEM software should not be sold - it is sold as part of compatible hardware. Immediately report the seller to eBay and the authorities. Don't be scared to take the seller to task.
Thanks for reading this guide.