[jkyle]

Only if you view CPI in isolation as money from the sky.

Marketers estimate the CPI they're willing to pay based on estimated conversions per impression. Ultimately, the money comes from sales. It always comes from sales.

If I don't ever purchase anything from a website ad, my impressions are worth zero. My impressions, and impressions by those like me, will drive down the price a company is willing to pay per impression since the conversion ratio also goes down. In fact, my impressions incur a negative effect since it still incurs a cost to the advertiser.

In the best of all possible worlds, only those who will ultimately buy a product are displayed the ad. Resulting in a 100% conversion ratio. Each impression would be maximally valuable and the price paid for that impression would rise to reflect that.

Those of us who use adblock have removed ourself from the market and from the conversion ratio calculations and cost per impression to the advertiser.