This study assessed bets advertised on Twitter by betting operators and affiliates, as well as their success. Bets advertised by 10 Twitter accounts were tracked over two weeks. Information recorded included: bet odds, bet type, number of times advertised, and bet success. The success of bets was calculated based upon placing equal stakes on each bet and running four sets of 10,000 simulations, each of an increasing number of randomly chosen bets with fixed bet stake per bet from those recorded. Both operators and affiliates advertised around 140 bets per day at average decimal odds of 6.0, however affiliates posted each bet three-times more than operators. Only one-in-five bets advertised won. Affiliate bets led to a 12% loss of original stakes, whilst operator bets led to a 20% loss. Only 30% of 10,000 simulations of 14 randomly chosen bets led to profit, decreasing to 19% when the number of bets included in the simulation increased to 140. Findings raise concerns about the volume of bets advertised on social media with large expected losses. Simulation data demonstrates how the chance of making a profit decreases the more advertised bets are bet upon. Future research should explore bettors’ responses to such marketing.