The number of times certain words appear in the content of a hub with good links can greatly influence why the hub will show up in a search.
Often people who optimize websites will use this trick to improve search ratings for a site.
On YouTube it's called "Rick Rolling". Usually it's a title that has little to do with the actual content of the site then repeating those words in tags.
For instance mentioning Justin Beiber even though the article or video has nothing to do with him.
The very fact that I mentioned his name in this answer actually guarantees this answer will now be indexed by Google.
But to be sure I have to say Justin Beiber again or Justin Beiber will not be indexed so high.
Are you getting it Justin Beiber?