A while ago I noted that a lot of this Fall seasons premieres benefited heavily from time-shifted viewing. More recent ratings numbers suggest that the impact is not limited to sampling new series. Many of the most popular TV series are continuing to see 40-50% of their audiences time-shifting. Looking at the Nielsen L7 (live viewing plus time-shifted viewing within a week) ratings for the key 18-49 demographic.
Thus far in 2012, the top 10 broadcast shows have been getting 45.6% of its total audience (looking at its live premiere episode broadcast and seven days that followed) from time-shifted viewing. This compares to 41.6% in 2011.Shows pulling more than half their viewing from time-shifting include Big Bang Theory, Modern Family, Revolution, and New Girl (tops with 59% time-shifted). The rest of the top 10 series had time-shifting of 40% or higher, with the exception of Elementary (which narrowly missed at 39%). Analysts note that the median age of viewers drops when time-shifting viewing is included, suggesting that younger folks make heavier use of their DVRs. Penetration of DVR devices/services in US TVHHs continues to expand, passing 45% this summer, but cannot account for all of the increase in time-shifting on its own. TV viewing habits seem to be changing, particularly among younger viewers.
Source - More Broadcast Hits Seen Through Time-Shifting, Media Daily News