The new Google Panda Update gives more credit to something called the "Bounce Rate"
Bounce Rate Rb =(Tv/Te)
Rb = Bounce Rate
Tv = Total Number of visits viewing one page only
Te = Total Entries to page.
Social networks and Blogs have to find things for people to do in order for them to remain on the site. Youtube used to have "adding friends" to keep people on it all day long. Basically the more time you spend on a site , the more points it gets with Google. If people are given incentives to spend more time on Hubapes (rewards and scores) then it is likely that people will spend more time and make the site more valuable. That is my guess- OK?
These days everyone is being followed by internet cookies and so Google knows where you came from, what you are doing on HubPages, how long you spent on it and where you go afterwards. They are not the only ones fishing for this information and probably everyone using cookie technology is doing this. This is the age of the COOKIES my friends!