Forgetting that a lot of improv comedy stinks, ad agency 18 Feet & Rising is partnering with British improv troupe Mischief Theatre to produce a live ad that will air on U.K. Comedy Central on the evening of June 17. The idea is simple: With no advance preparation, the Mischief players will get three minutes to improvise an ad live on the air for a product selected without their knowledge beforehand. Three-minute ads are too much when the material is written ahead of time, but I have to admire Mischief's willingness to take this project on. Pulling a legitimate commercial—even a bad one—out of thin air is no easy task, although it's probably more pleasant than soliciting topics from a typical improv comedy audience.