Exhibit 21.1 LIST OF SUBSIDIARY CORPORATIONS ZDNet, Inc., a Delaware corporation ZD, Inc., a Delaware corporation mySimon, Inc., a California corporation CNET Marketplaces, Inc., a Delaware corporation CNET Europe, S.A., a Swiss corporation, doing business as CNET Data Services CNET Investments, Inc., a Delaware corporation CNET Investments II, Inc., a Delaware corporation ZDNet Europe, CV, a Netherlands partnership ZDNet Global, BV, a Netherlands corporation ZDNet Holdings, BV, a Netherlands corporation