Time was that DVRs were going to destroy TV's ad-supported model. But a new Nielsen report shows viewers watch a notable amount of commercials that they could zap, which is helping increase C3 ratings, the industry currency. The research shows that C3 ratings rise 16%, thanks to people watching commercials while using a DVR. That data is for 18- to-49-year-olds for ABC, CBS, CW, Fox and NBC combined. The commercial viewing average for the networks' live feeds -- during the April 29-May 26 period -- was a 1.78, which rose to a 2.06 for C3. C3 ratings take into account commercial viewing for a live broadcast, plus over the ensuing three days with DVRs. There is further evidence that commercials are being watched during delayed viewing: Nielsen found that in homes with DVRs, commercials viewed in time-shifted mode boost C3 ratings by 44%. That's also among 18- to-49-year-olds for ABC, CBS, CW, Fox and NBC combined. Nielsen found that overall, about 50% of broadcast program viewing with a DVR takes place on the same day it is recorded. That measure indicates some people are eager to watch shows live, but are content to wait a bit to avoid ads. DVRs are now in 38% of U.S. homes, and Nielsen says homes with DVRs consume more prime-time programming than those without the devices.