Those 5 sites are a plague on the internet. They toss poor workers pennies to churn out reams of forgettable content which clogs up the search results because of the huge authority of those sites. Most of the writers simply research the content at other websites and rehash the exact same ideas. If they even attempt to credit their sources with a backlink, those links are always nofollowed, with pagerank only allowed to pass to related internal pages. The ones that do allow followed links (Squidoo) are relentlessly spammed. The result is bad for users and smaller competing sites. I remember reading on the eHow CEO's twitter page how they produce the amount of words equivalent to War and Peace every day, as if flooding the web with more watered down garbage was doing the world a favor.
