Judging from the listings on the major online bookstores, the whole world is in love with jokes, and books of jokes to such an extent, well, almost as much as it loves Paris Hilton.
But what jokes exactly? We did a random search on several sites and came up with some interesting results.
Using the keyword "jokes", it was an eye-opener when a single site found 54540 books involving gi jane joke listed in its database. This was kind of strange in a way.

When last did you check out a friend's book shelf at their place? We are prepared to bet that books of jokes did not feature much, if at all. Most likely there were relationship books, car manuals, sports books, glossy novels, a gift books, unopened textbooks.
Perhaps there was a ragged cartoon book at the end of the shelf and one in the bathroom.

So what are all these listed joke books exactly?

At the bottom of the price range ($1) we found Spongebob, Rugrats, Dumb and Dumber Garfield and hundreds in the 101 Jokes series: 101 Vacation Jokes, 101 Telephone Jokes, 101 Pet Jokes - you get the picture. Some jovial publisher obviously figured out also that the entire world loves a good joke or more than a hundred preferably.
It is interesting too that so many of the books of jokes in this price range are aimed at kids. Books containing "Children's good clean jokes" is a recurring theme here.