FCC Chairman Michael Powell once famously referred to TiVo as “God’s machine.” I wouldn’t go that far, but having a DVR is pretty awesome. Watch when you want, pause live TV, never miss an episode of your favorite series. You collect TV shows, rather than just watching what happens to be on right this second.

But most television is based (in part) on advertising revenue and there has been much nervousness about DVRs, given the possibility that viewers might just skip through ads. A new study from Magna Global says otherwise, according to a story in Media Life Magazine:

As it turns out, almost all ads are still seen by TV viewers, either live or when shows are seen in playback. Ad-skipping is minimal.

About three-fourths of all commercials viewed in DVR homes are viewed live, meaning as a program originally airs.

When ads seen during DVR playback over three days from the original airing are added in, the share of ads seen by viewers rises to 97 percent, according to a new report from media buying giant Magna Global.

Further, the study found that for DVR-recorded ads, about half are viewed the same day as the original broadcast, and roughly 90 percent are watched within three days.

That could change as DVRs and their use become more common. As more shows are recorded, presumably fewer would be watched and fewer would be watched in the days immediately after they were recorded.

But with DVRs now in some 21 percent of all homes, most demographic groups watch the vast majority of recorded commercials within a few days, and it doesn’t vary much by age group.

I don’t have an up-to-date statistic, but SNL Kagan had previously estimated 11 million cable customers with DVRs for the end of 2007.