Grand-averaged transit light curves obtained from various datasets. White: our basic set of 32 LCs as presented in Sect. 6; gray: 32 LCs from the basic set and 13 LCs recommended by the referee from the ETD in her/his second report. (These LCs come from the following followups (name-date-filter): CLopresti-2010-09-11-R, SGajdos-2010-10-27-V, SKorotkiy-2010-10-25-R, JGarlitz-2010-11-19-R, LBrat-2010-11-27-C, Dhusar-2010-12-03-R, SShadick-2011-02-10-I, DSergison-2011-09-29-R, CGillier-2011-09-29-R, SShadick-2011-10-01-I, SShadick-2011-10-30-I, ABourdanov-2011-12-10-C, ERomas-2011-12-10-B.) Black: as for the gray set but omitting 11 stars recommended by the referee in her/his 3rd report. (These omitted LCs come from the following followups (name-date-filter): SGajdos-2010-10-27-V, SKorotkiy-2010-10-25-R, LBrat-2010-11-27-C, and #6, #15, #18, #24, #26, #33, #34, #36 from our basic set as given in Table 1). Notation and data sampling is the same as in Fig. 10. The residuals have been shifted vertically for better visibility.