Tablets (read- iPad) are Prime-Time devices

One of the questions since the tablet (iPad) boom started, is how are consumers using these devices? When are they using their iPad?
This graph from Paid Content shows that tablet usage peaks in prime time, from 6pm to midnight. While mobile usage peaks around consumer commutes and computer usage is high during work hours, the lean back experience of tablet peaks during TV-watching hours.
There is a big opportunity here for advertisers to disrupt or complement their prime-time TV experience.