Comcast's rhymes with:
broadcasts, newscasts, outcasts, telecasts, broadcasts, chloroplasts, enthusiasts, newscasts, outcasts, outlasts, telecasts
Comcast's sounds like:
chemists, coincides, communicates, communist's, communists, communists', comsat's, comstock, concedes, conestoga, conjugates, connaught's, connects, conquest's, conquests, consists, constitutes