I would have assumed that competitor sites were the most relevant comparison to draw. It is highly likely that Destructoid sees a higher rate of ad-blocking than, say, yahoo.com, but that's not really relevant as Destructoid isn't competing with Yahoo!.
While having having X readers PLUS the infrastructure costs to support X readers, they see the same revenue as more general sites having X/2 readers.
If there weren't ad-blockers, the absolute reader count would be the only thing that mattered.
As it was in the press era. It didn't matter if you were the New York Times or the LISP Quarterly, if you had managed to have X readers you got the same amount of ad money (well, not 100% the same, because it also depended on the demographic, but LISP and NYT would rank close enough).
