In this research we recalibrated the peoplemeter in the AGB McNair New Zealand Peoplemeter Panel to produce second by second ratings, instead of the usual one minute ratings. We looked at audience ebb and flow during programmes, and, in particular, during commercial breaks. In contrast to previous research into audience behaviour during ad breaks, the peoplemeter is entirely unobtrusive and potentially measures what people actually do instead of what they say they do. The audience levels show a surprising amount of change, not just during commercial breaks and between programmes but even during programmes. A number of programmes show considerable build in audience in the first ten minutes. On the other hand, soaps, for instance, show strong viewer loyalty, even during advertising breaks. One of the major purposes of this research was to study television audience levels during commercial breaks. We show that television ratings drop during commercial breaks, but only by 5%. Furthermore, we show that viewers are potentially exposed to 90% of the content of the commercial break shown on the channel they were tuned to prior to the start of the break. We also show that ad avoidance is largely done at random, that is, there are very few personal or household characteristics that correlate with ad avoidance behaviour. Furthermore, it appears that characteristics of the ad break, such as number of ads in the break and length of ads, have an affect on the ad break ratings, but they are not substantial. Lastly, it is evident that viewers sense the timing pattern of ad breaks and their ad avoidance behaviour is dictated somewhat by this sense of patterning.