WordNet (r) 3.0 (2006):

sellout
    n 1: an act of betrayal

Moby Thesaurus II by Grady Ward, 1.0:

27 Moby Thesaurus words for "sellout":
   Judas kiss, betrayal, consumer preference study, consumer research,
   consumer survey, direct-mail selling, double cross, hard sell,
   hawking, high-pressure salesmanship, huckstering, jobbing,
   low-pressure salesmanship, mail-order selling, market research,
   marketing, marketing research, merchandising, peddling, promotion,
   retailing, sales campaign, sales promotion, salesmanship, selling,
   soft sell, wholesaling