Best Answer - Chosen by Voters
From Wikepedia :-
"cc.cc, co.cc, cu.cc are not official hierarchies; they are domains owned by companies who offer free subdomain registration."
In other words, cu.cc is a cost free name that ANYONE can 'register' without paying one cent ..
Now, who do YOU think is more likley to 'register' with a company offering free domains .. a real business or a POOR DUMB SCAM MERCHANT ???
FYI - clever scam merchants pay for real domains ... this makes it harder for the victim to spot the scam in advance ..