Search engine users click the results listings' top entry much more often than can be explained by relevancy ratings. Once again, people tend to stick to the defaults.
M. Costa, D. Gomes, F. Couto, and M. Silva. Proceedings of the 22nd International Conference on World Wide Web Companion, page 1045--1050. Republic and Canton of Geneva, Switzerland, International World Wide Web Conferences Steering Committee, (2013)