1. A computer-implemented method performed by a data processing apparatus, comprising: determining a respective approval metric for each of a plurality of content submissions, the respective approval metric being at least partially based on a number of favorability indications associated with the content submission, wherein each favorability indication indicates either positive or negative favorability; determining a statistical upper bound for the respective approval metric of each content submission according to a first scaling method that scales up the current value of the respective approval metric by a decreasing amount with an increasing number of favorability indications that are associated with the content submission; generating a priority ranking for the plurality of content submissions according to the statistical upper bound calculated for the respective approval metric of each of the content submissions; and selecting one or more content submissions in the priority ranking as featured content submissions to elicit votes from users, the selecting occurring according to respective ranks of the one or more content submissions in the priority ranking.