It is hilarious that you use fights like Hendrick/Pierce and Condit/Kim as if they sold those PPVs. Yea, UFC 141 didn't sell because of Brock vs. Overeem. It was all because of Hendricks/Fitch.
Your logic is laughable.
No, Diaz/GSP didn't sell much more than vs Shields or Hardy. But if you would do a little more research you would understand that the golden era of PPV sales as passed. 500,000 buys is good numbers these days. 500,000 a couple of years ago would have been a very average PPV. People don't buy PPVs as a whole as much as they used too. Streaming and the amount of events is probably a good reason why.
Yeah, I suspect that attributing Hendricks drawing power to the sales of 141 is pretty laughable ... about the same level of laughable as attributing 158 draw to anything to do with Diaz, especially when GSP can fight Hardy on a card not nearly as stacked or important in terms of contender standings and draw the same numbers.
In the last couple of years, when you claim 500K is a good number (and which I tend to agree,) GSP fights have consistently drawn in 800K range .. so let's not pretend that the 800K had anything more to do with Diaz as it did having Condit/Hendricks and Ellenberger/Marquardt on the card.
GSP draws, Diaz doesn't ... I see no proof that Diaz has any drawing power, except drawing media for a quick and easy controversial and stupid comment.