Why do people get a new domain name for every little thing they offer?

[zenba]

i still don't understand why subdomains didn't get wildly popular. most places don't even charge ya for em anymore. i remember the best free hosts were the ones that gave you subdomains off their main domain as opposed to a forwardslash.

i can see why a company would want to snatch up a bunch of similar domains in order to prevent fraud and scams, but they should all redirect to the main domain.