Timeshifting's Ratings Impact

When I recently posted some comments on the cable/broadcast battle to claim supremacy, I noted that same-day timeshifted viewing had grown significantly.  The Hollywood Reporter also noted the change in their review of the start of the Fall 2012 season.  With DVRs (digital video recorders) in about 46% of US TV households, younger viewers in particular seem to be actively embracing the potential to adapt their TV viewing to there own lifestyles, rather than shifting their daily habits to watch TV.
  To back this up, the piece compared ratings for this season among young adults (18-49) that combined live viewing with three days worth of delayed viewing with the traditional ratings based on live viewing.  In aggregate, the 18-49 audience for the four networks primetime premiere week (excluding sports and Saturday) was 41% larger when you included those who timeshifted and watched the program within three days. 
  The article also provided some more specific comparisons in terms of viewing of returning series - NBC's Revolution L+3 viewing was up 50%, making it the most timeshifted program in NBC's history ; CNS's Vegas was 28% higher with timeshifing; ABC's Modern Family added 33% to its rating when including delayed viewing.
  Now, that's just a few, so I went back to the TVB study to crank out some more numbers on the level of timeshifting we're seeing so far this Fall.  The ratings are for the previous week and for the 35-54 demographic, and the report reported delayed or timeshifted viewing within one day of the original airing.  Thus the numbers aren't directly comparable to those above.  The report also reported viewing only for the top primetime programs.  I'll list the programs and the share of one day timeshifted audience

Modern Family 32%;; Big Bang Theory 31%; Grey's Anatomy 28%; NCIS 25%; How I Met Your Mother 31 %; Survivor: Philipines 29%; 2 Broke Girls 26%; New Girl SPL 40%; Voice (Tues) 20%; Once Upon a Time 24%; Amazing Race 21 29%; Mike & Molly 25%; Revenge 25%; Two and a Half Men 20%; New Girl 29%; The Middle 22%; NCIS: Los Angeles 16%; Office 33%; X-Factor (Wed) 19%

The quantitative side will note that this is anecdotal and a limited nonrandom sample, so don't take the precise numbers as gospel.  Still, the numbers show a significant level of timeshifted viewing.
Another caveat was the point made by David Poltrack, chief research officer at CBS - that timeshifting during premiere week may also be driven by people wanting to sample new programs.
From the network perspective, that's good news, "because sampling is what it's all about."

  It seems that DVRs and timeshifting have caught on, at least with some demographic groups,  The levels are high enough to make a strong case for networks and advertisers to put more of an emphasis on using ratings measures that include at least some delayed viewing.  The might also consider the long term impact of delayed viewing on program scheduling strategies.

Source -  DVRs Dramatically Altering Fall TV Battleground, The Hollywood Reporter
Seasons of Premiers: Fall Broadcast and Summer Cable, TVB report

Editted to fix bad link for Hollywood Reporter source. (17Oct2012)