Advertisers and content providers are always free to negotiate the price of an ad impression. Because of Adblock, many "impressions" now go (measurably!) unseen

Advertisers and content providers are always free to negotiate the price of an ad impression. Because of Adblock, many "impressions" now go (measurably!) unseen. So ad prices will drop - and in response, ad volume will go up. But advertising budgets haven't changed! The world's marketing departments still have $X to spend on web ads, and the world's content providers get $X. The only thing that's changed is that they're now exclusively targeting the segment of people who don't use Adblock: customers who view web ads as useful/relevant and convert via that method more often. There's nothing unethical about blocking ads. Nor will it be unethical when content providers introduce subscription models, or when advertisers buy up half the page. It's simply a big structural change in the market: ads are no longer deliverable to all users. Eventually we'll all realize that web content is excludable (e.g. Netflix), and I suspect a lot more sites will move towards a hybrid model to capture revenue from ad-haters as well.