>The creators of the content allow anyone to view it, regardless of whether they run an ad blocker or not. Sometimes, they place alternative content where the ads would be, requesting that I disable my ad blocker, or like them on facebook as an alternative.

So would you suggest (or would you even use) AdBlockers identify themselves to the website (so I can write "if($_SERVER["AdBlocker]){echo "Sorry, see ads or leave}"?

Because there are adblock blockers, and people write _adblock-blocker-blockers_.