The authors examine the efficacy of shifting consumers towards zero calorie beverages. Three sites in the U.S. received 5 interventions in the period Oct 2009-May 2010; (1) a 10% discount on zero-calorie beverages, (2) the 10% discount + discount messaging, (3) messaging comparing calorie information of sugar beverages with zero-calorie alternatives, (4) messaging comparing exercise equivalent information and (5) messaging comparing both calorie and exercise equivalent information. The main outcome measure was daily sales of zero-cal and sugared beverages.Results failed to demonstrate a consistent effect across interventions. Treatments (2) and (3) had statistically significant effects: the former saw an increase in purchases of zero-cal beverages, the latter saw an increase in sugarbeverage sales.