What's the optimal length (in seconds) of a pre-roll ad?

Zero.

That's the answer I gave to Executive Editor of iMediaConnection.com, Brad Berens, when he recently quizzed a bunch of interactive industry execs.

I told him that as long as I had any say in it, I would never purchase or advise a client of mine to purchase a pre-roll commercial on the Web.

It's a cheap imitation of a failing business model - it is intrusive, disruptive, one-size-fits-all, linear....you get the picture.

SMG's Digital Chief at GM Planworks, Curt Hecht, weighs in with a similar view reported in MediaPost.