Remember when TPM came out and Lucas said all the trailers in front of it had to be 30 seconds or less? What an ass!
No, the request was that no more than three trailers total could be attached. 20th Century Fox, realizing this, created a trailer that combined two different combination of 3 30 second ads: Titan AE, The Beach, and either Anna and the King, or Fight Club. So that way, they could get 3 times the trailer exposure than any other company that happened to get their trailers attached to the movie. The 30 second triple trailer idea was all 20th Century Fox, not Lucas.
Not that it really mattered. Lucas also requested that only THX theaters play his movie. Neither request was followed by all the chains. Many of them attached 5 or 6 trailers, and a lot of those screenings were in theaters NOT certified by THX. Although a lot of theaters scrambled to get their screens certified in time.