Companies and individuals are allowed to patent anything, regardless of whether it is actually being brought to market. So I can patent, say, a new cool website service and I don't have to actually have a website that does what my patent says. For example, people patented photo sharing web sites before there were photo sharing websites. Now all photo sharing websites (flickr, picasa, facebook, etc) have to pay royalties to the patent holder(s).
Even worse, even well meaning patents are often sold to patent "trolls", who don't have any products, but rather make all their money by suing others. Help encourage innovation by only allowing companies / individuals to own patents to protect their products.