Why does every man and his dog put man pages online?

So, I know that I have a few man pages online, but then again I wrote either the code they document, or some of the generation toolchain to create them, so I think that is different. Why does every man and his dog feel that he should put man pages online? It actually makes it really hard to search for things if the first page of Google results are the same man page over and over again from sites who seem to think that they’re making a contribution to the community.

Are they just doing this to grab some pagerank?