Penn Entertainment’s (NASDAQ: PENN) ESPN Bet mobile sportsbook, launched just over a year ago, is already showing benefits from its association with the renowned sports broadcast network. A recent YouGov survey ranks ESPN Bet as the fifth-largest sportsbook operator in the U.S., behind DraftKings, FanDuel, BetMGM, and Caesars Sportsbook. However, ESPN Bet’s affiliation with “the…