Gumtree wished to increase brand awareness and engagement on Facebook. They developed a sweepstakes app with a celebrity ad guessing game and prize of £500. Users were prompted to like the page and enter personal details. The app increased likes by 41.8% and those talking about it by 6,000%. Promoted posts reached current fans and their friends, boosting entries. While not all potential fans saw it, the viral sharing incentivized organic growth. Gumtree should continue incentivized competitions across platforms for engagement.