Hey man.
Is it too simplistic to suggest that PPV buys are down in WWE due to the level of matches that we get for free on RAW, especially with the change to 3 hours. This past RAW, we had:
Punk/Mysterio, Orton/Big Show, Kane/Miz, Del Rio/Christian and Cena/Bryan
Throw in a Sheamus match (Ziggler maybe) and you have a card that could EASILY constitute a regular PPV. Hell, add HHH/Lesnar and this card wouldn't look out of place as a Summerslam!

It is very simplistic, yes, because they were doing the same thing from the start of the Monday Night Wars until PPV buyrates started to die off, so you can't really do any causal thing there.  I personally think it's a combination of raising the prices, oversaturation of the product, and just not creating stars that people want to pay money for.  In 2011 I paid money, real money out of my own pocket, because I wanted to see CM Punk both at a house show and on a couple of PPVs, so if even a jaded super-smark like me can still be sold, then others can as well.  And I WANT to be sold!  That's why I harp on PPV builds so much, because I WANT them to talk me into spending money on the product!