"Lerman and Hogg found that position bias accounts for consumers spending five times more attention on material that is posted near the top of a webpage. Position bias can be a potential problem for sites that rely on peer recommendation alone. For example, Reddit posts appear in order of popularity, derived from up-votes and down-votes by users, with more popular posts nearer the top of the webpage. Due to position bias, users are more likely to see, consume, and recommend already-popular content positioned near the top of the webpage, creating a run-away loop that further amplifies its popularity at the expense of potentially more interesting content farther down the webpage.
"In their study, Lerman and Hogg demonstrated that ordering content by recency of recommendation rather than by aggregate popularity (total 'likes' or recommendations), generates better estimates of what users actually find interesting and would prefer to consume."