WordNet (r) 3.0 (2006):

cash in on
    v 1: take advantage of or capitalize on

Moby Thesaurus II by Grady Ward, 1.0:

33 Moby Thesaurus words for "cash in on":
   benefit from, capitalize on, carpe diem, cash in, clean up, clear,
   coin money, commercialize, exploit, gain by, gross, improve,
   improve the occasion, make a killing, make capital of, make hay,
   make money, make money by, net, not be behindhand, profit,
   profit by, put to advantage, realize, realize on, seize the day,
   take advantage of, trade on, turn a penny, turn to account,
   turn to profit, turn to use, use to advantage