I don't have Tivo but I have something similar; DVR (Digital Video Recorder) from Time Warner Cable. I agree with jumpjet about the pause/rewind/fast-forward features. Now, if an hour-long show starts at 9 and I'm not ready to sit down and watch it, I'll hit record, do something else until about 9:20, and then watch it (skipping through the commercials) and I'm done at the same time.
Last night I was laying in bed, knowing that I needed to get to sleep, but something I was interested in was on TV. It took me 20 minutes before I realized I could just hit "record" on the box and watch it this morning...which I did.
DVR from my cable company is cheaper than Tivo ($6.95 extra a month) and I don't know how I lived without it.
I don't think I watch more TV, I just watch better TV.