Half of DVR owners had watched shows online, but just four percent do so on a weekly basis, according to Performics.

Google's DoubleClick Performics unit examined the commercial watching behavior of 500 viewers.

35 percent of DVR owners said they pay attention to ads seen on TV. But only nine percent said paid attention to ads online. And 38 percent said online spots command less of their attention.

22 percent of DVR owners said they would watch more shows online — good news for networks like NBC and ABC, which liberally stream their most popular shows. For its part, ABC plans to pump more ads into episode breaks — which would lengthen the time between shows significantly.