It is a pointless gimmick.

I think it's just useless.

Such names (for example in *.tv zone) is simple to remember when it can be spelled without problems (I can hardly spell codeforc.es), that's why advertising sites use them, but codeforces is out of this sphere.

The only reason CF command may need to buy "codeforc.es" is to prevent possible spam/fraud attacks. But still, there is no public money streams -> no commercial (just prestige) competition with other projects -> no attacks, account stealing, political actions, etc. So, again — most probably this purchase will be useless.