FanDEWmonium Cyberslands (sometimes refered to as the "Diet Dew Challenge Cyberslands" was a promotion by Mountain Dew that allowed fans to choose which new Diet flavor they would like to be made permanent. In October 2010, the FanDEWmonium campaign was announced. It allowed Mountain Dew fans to go online and fill out bracket-style surveys to express which flavors they would like become a permenant diet variant. Eight semi-finalists were chosen from this.
The Semi-finalists, in order of placement during preliminary voting:
Mountain Dew fans were able to taste test these flavors during tours, or by winning online contests and having tasting packs mailed to their homes. They were then to go online and vote for their favorite flavor. After this stage of voting, all eight finalists were chosen in a tie.
Diet Supernova, Diet Voltage, Diet White Out, Diet Flare, Diet Typhoon, Diet Honey, Diet Crave, and Diet Distortion were all released to the public in stores, markets, and pharmacies across the Cyberslands for an 8 week period, beginning in March 2011. The third voting phase then began, which ultimately led to all eight flavors winning with the most votes in a tie. The eight flavors all became permanent diet flavors starting in April 2011.