"502 be willing to pay for only “live” viewing audiences, if they believe VTR viewers will delete commercials or if rating services are unable to measure VTR use; if this is the case, VTR recording could reduce the license fees the Studios are able to charge even for first-run showings. Library-building may raise the potential for each of the types of harm identified by the Studios, and time-shifting may raise the potential for substantial harm as well. 8 8 A VTR owner who has taped a favorite movie for repeated viewing will be less likely to rent or buy a tape containing the same movie, watch a televised rerun, or pay to see the movie at a theater. Although time-shifting may not replace theater or rerun viewing or the purchase of prerecorded tapes or discs, it may well replace rental usage; a VTR user who has recorded a first-run movie for later viewing will have no need to rent a copy when he wants to see it. Both library-builders and time-shifters may avoid commercials; the library builder may use the pause control to record without them, and all users may fast-forward through commercials on playback. The Studios introduced expert testimony that both time-shifting and librarying would tend to decrease their revenue from copyrighted works. See 480 F.Supp., at 440. The District C ourt’s findings also show substantial library - building and avoidance of commercials. Both sides submitted surveys showing that the average Betamax user owns between 25 and 32 tapes. The Studios’ survey showed that at least 40% of users had more than 10 tap es in a “library”; Sony’s survey showed that more than 40% of users planned to view their tapes more than once; and both sides’ surveys showed that commercials were avoided at least 25% of the time. Id., at 438-439."