Data sharing has the potential to facilitate wider collaboration and foster scientific progress. But while 88% of researchers in a recent study confirmed they would like to use shared data, only 13% had actually made their own data publicly available. Benedikt Fecher, Sascha Friesike, Marcel Hebing, Stephanie Linek, and Armin Sauermann look at the mismatch between ideal and reality and argue that academia is a reputation economy, an exchange system that is not driven by monetary incentives, nor the desire for scientific progress, but by individual reputation. Data sharing will only be widely adopted among research professionals if it pays in the form of reputation.