1/ large e-commerce type sites like amazon, ebay etc.. - Bad Sign, Hard to Beat.
2/ youtube.com and other video sites ... - Mixed signs, Can be Hard but May be Beatable if PA is low.
3/ forums and answer type sites like answers.yahoo.com, yelp.com, quora.com, warriorforum.com etc... - Good Sign, Normally Not Too Hard to Beat.
4/ government sites, wikipedia.org, wikihow.com, high authority health sites like mayoclinic.com, webmd.com etc.. - Bad Sign, Hard to Beat.
5/ niche sites - Usually a Good Sign - Likely to be Easy to Beat.
6/ personal blogs - Good Sign - Often Very Beatable.
7/ social media sites like facebook.com, twitter.com, reddit.com - Mixed Signs, if big brand will be Hard to Beat.
8/ big brand sites like addidas, microsoft, magazines etc.. Bad Sign, Hard to Beat.
Have I forgotten any? Do you agree with the above?