In my experience as an user, no website has ever beaten an ad blocker. It's like trying to secure a computer against an adversary with full physical access. The content has left the server and is on the user's machine. Nothing can stop a sufficiently determined user from consuming it, with or without ads.
I answered a question on User Experience.SE about this:
http://ux.stackexchange.com/a/96907/3437
I tried to express just how big the power disparity between the developer and the user is. Looking back now, I think I came off as too extreme.
I think the other answers are excellent; they address the UX aspects in a way I wasn't able to. Definitely learned from them.