Ever consider making the website generate its own revenue, such as by offering a service which cannot be performed by a computer, or selling a product of your own?
Let's face facts: If your OMGPoniez111!! site can't generate a self-sustaining revenue stream, you're doing it as a hobby. To finance your hobby based on advertisements would be akin to finding sponsors who would pay to have their logos placed on model cars.
This isn't some high-minded debate about the nature of freedom, economic theory, and morality. This is a matter of basic human behavior and convenience; do you read every advert in the newspaper? Watch every commercial on TV? Who owns your fucking eyeballs, anyway?
Here's something for the authoritarians in the audience to contemplate: I own my own computer. What I choose to download is my business. If you make my life hard for it, I will remember. If you screw with me too much, I'll revenge.
A well-known fact about business, as a field of study, is that a satisfied customer will tell three or four friends how good your service was. A dissatisfied one will tell everyone he knows how dissatisfied he is.
The genie is out of the bottle on this one, at any rate. As long as one can write code, and download code written by others, there will never be a way to "enforce" ad viewership.
So, the lesson is, if people aren't willing to pay you, directly, to look at OMGPOniezz!!!1!!.wank, then either you need to reevaluate how important your hobby is to you, make your content good enough to be worth buying, or subsidize your pet projects from your own pocket, just like the rest of us have to.