Humor is generally a delicate thing; subtlety often works better than broad gestures. There's an element of intelligence associated with the different types of humor; that is, subtle humor relies on the intelligence of the viewer/reader to put together the pieces and see the humor, while broad humor literally hits you in the head.
A member of my book group selected the novel A Dirty Job by Christopher Moore for out next reading, and the cover blurbs warn of Moore's absurdist take on life. It's a parallel route to the one I ascribed to Fritz Leiber—Leiber shows us normal people and inserts elements of the supernatural into their lives in order for us to see their attempts at dealing with them. A Dirty Job, on the other hand, takes normal people and inserts elements of the absurd into their lives. Specifically, the protagonist finds out that he has the power to collect the souls of people about to die, but he is not given the instruction manual for those powers (literally—The Big Book of Death does not make into his hands) and fumbles his way through life and death. To add to the potential humor of this situation (think Greatest American Hero meets Neil Gaiman), Moore insists on stereotyping his protagonist, Charlie Asher, as a "Beta Male" in order to make swipes at the ridiculous nature of the way average people live their lives.
Unfortunately, the potentially interesting plot is undercut by its use as a foundation for really broad humor and scenes intended merely to shock. To be honest, there are moments in A Dirty Job that are chuckleworthy, but sometimes the humor misses wildly (it may just not be my kind of humor) or it all gets stacked up on top of each other so that it threatens to overwhelm the reader rather than amuse him. Moore inhabits his story with diverse and thus also potentially funny characters, but they are so predicated on stereotypes that the humor again seems to get away from the writer. At its core, the story is about making joke after joke, while the plot languishes and only advances in fits and starts. In hands less heavy, this could have been a delightfully charming book, but I found myself rolling my eyes much as I do when someone insists on making bad pun after bad pun.
Finally, A Dirty Job just points out to me how difficult the job of a comedy writer really is, making that much more thankful for the speculative fiction writers who have succeeded at it, like Douglas Adams and Robert Aspirin. (And a note to the publisher—if you insist of trying to insert a semi-serious plotline amidst the comedy, perhaps you should give away a huge spoiler on the very cover of the book!)