it's very uneven in style, contradictory in many places. and quite rife with factual and historical errors. aside from the flaws, it seems to enjoy a considerable amount of success and lots of people seem to really like it.
the first chapter contains a neat and quite beautiful story that was used to explain the origin of the universe, and in more detail, of the earth and man. during the time of its initial publication, the people were considerably supernatural in their beliefs and knew little about the nature of the universe, and this seemed to seem a likely explanation as any.
there are some interesting characters in the book. there's one guy noah who builds a boat to house a pair of each of the millions of species to save them from a flood which covered the earth. there's a bush that is on fire that talks. half-way through the book, a new character is introduced by the name of jesus. the book pretty much concerns itself with his adventures throughout most of the remainder of the book. he is magic and is friends with everyone, from prostitutes to lepers to even dead people, who he can resuscitate. the character is interesting, but is quite derivative. there are simply too many other characters in literature that share this character's backstory and character arc for him to be a true original. many of the details surrounding this character can be traced to similar characters such as krishna, adonis, bacchus, osirus, and many others. there is a new twist put on this character, however, and it seems most people overlook the fact that the writers borrowed so much from other works.
one problem i have with the book is with the consistency of a character called god. in the beginning he is a real prick. he does an awful lot of smiting. he also kills a lot of people (somewhere in the neighborhood of 300,000) and commands others to kill even more. he even destroys whole cities (60 i believe). he endorses slavery, human sacrifice, selling of your daughter as a sex slave, and even bashing babies against rocks. but somewhere about half-way through the book the character has a complete 180 degree turnaround and becomes a really nice guy. i don't know if the writers did a good job of illustrating this epiphany and there needs to be more exposition regarding his change of heart.
the last chapter is totally weird and rivals anything william s. burroughs ever wrote in terms of its hallucinatory depictions and surreal narrative.
overall, i felt this book was ok, if you can overlook the above mentioned flaws, and general stilted nature of the dialogue (who really talks like that, anyway?). personally, i don't see what the big deal is. but i didn't really like chuck palahniuk either, and lots of folks really think he's something else.