LOS ANGELES (AP) - Pay TV customers who are used to watching fewer ads on on-demand shows may have to put up with longer commercial breaks. Comcast Corp., the nation's largest cable TV provider, says it is testing out a system with its NBCUniversal subsidiary to use full commercial loads on older episodes - while disabling fast-forwarding of ads - if consumers watch them within three days after a new episode airs. Currently, if people binge-watch to catch up on shows like "The Blacklist" or "CSI," they only see the full ad load on the most-recent episode. Older episodes have few if any ads. Comcast says putting full ad loads on older shows will help generate more revenue for networks and encourage them to make more shows available for on-demand viewing. "The trade-off is (consumers) are getting access to much more content," said Matt Strauss, Comcast's senior vice president of video services. Strauss said that consumers appear to not mind the ads. Even when consumers can fast-forward past them, they only do so about half of the time, he said. Advertisers should also find the new system attractive because video on demand, or VOD, viewing is popular among younger people. The system could enable them to reach an audience they had missed with the live telecast. "The VOD viewer is upscale, younger and really more appealing to advertisers," said Brian Fuhrer, senior vice president of product leadership at Nielsen. Nielsen is working with Comcast to make sure the ads watched on older episodes count toward the so-called "C3" ratings measurement, which captures how many viewers watch commercials on the live telecast and on VOD and digital video recorders for the following 75 hours. Comcast has already tried out the system with the USA Network show "Psych" and plans to work with other networks soon. Fuhrer said the system could roll out early next year.