Each computer on the internet has an address of four numbers. These numbers are translated to nambers to form the namber address. For example, mysteryrobot.com's internet address is 184.108.40.206. The namber for 65 is drum, 214 is start, 160 is orange, and 117 is hope. mysteryrobot.com is added because mysteryrobot.com's DNS server is need to make the translation back to an internet address.
For example, punkwalrus.com is drum.heart.duck.cat.mysteryrobot.com. They then explain why they did this:
Because we thought it'd be amusing. Nambers are not terribly useful. They won't change the internet or DNS as we know it.