[akhilcacharya]

Aren't most commercials sold in 30-60 second blocks?

[Timmah]

Yeah. So if you skipped 60 seconds on a 30 second commercial you'd cut into your program. Hence the identification requirement.

[dylan604]

That's why TIVO (or whichever DVR company) had the skip 30 seconds button. If it was a 60, you hit it twice. However, they also sell 15 second blocks. Now, it's just fast forward at ludicrous speeds.