Cheech and Chong Simpsons Episode was Lowest Rated this Year

This just in....
Last night's episode of the Simpsons, starring Cheech and Chong, was the lowest rated Simpsons episode of the season.
Bummer!

The show was like a big advertisement for Cheech and Chong.  Was Fox paid for this or do they share agents with the Simpsons staff?