Apple’s iPhone has already killed the BlackBerry and maimed GPS units and pocket cameras. Is the online publishing industry next?

Some news outlets speculated as much after learning this week that it will soon be possible to block ads in Apple’s Safari Web browser. The company is adding a feature to help third party developers made extensions to the browser that filter and block content. Wired said the change “may upend how the Web works,” and the Nieman Journalism Lab predicted it would be “incredibly popular” and “shave off a real slice of mobile advertising revenue.”

Looking at what is known about who uses ad-blocking software, and how, suggests otherwise.

The suggestion that Apple customers are set to start strangling online publishers is based on the idea that millions of them will rush to block ads as soon as Apple rolls out version 9 of its iOS mobile operating system later this year. Millions of people do use ad-blocking software today. But data collected on the practice by the ad industry doesn’t make it sound like Apple’s move is about to suddenly add many millions more.

PageFair, an ad tech startup, released a lengthy report on ad blocking late last year in partnership with Adobe. It was titled “Adblocking Goes Mainstream” and included some striking figures. Every month 144 million people make use of ad blocking software, it said, approximately 5 percent of all people who use the Internet. PageFair also said that leading ad blockers are growing fast in popularity.

But the report also found that use of ad-blocking software is concentrated in a very particular demographic. Easy-to-install ad blockers are available for all desktop Web browsers, including Apple’s Safari. But almost all ad blocking is done by people using browsers that they have sought out and installed themselves. Usage in Safari is negligible, and PageFair’s report concludes that only a certain, technically minded demographic really cares about ad blocking.

“The less technical demographic hasn’t quite caught on to the concept … users of IE and Safari have not yet caught on to the trend.”

That doesn’t make it sound like millions of people are itching to block ads on their iPhone or iPad and will start doing so the moment it becomes possible. What PageFair calls the “less technical demographic”–otherwise known as “most people”–probably won’t be aware that you can even add extensions to the mobile version of Safari at all. Customizing your browser is a specialty interest on desktop computers and even more complicated and obscure on mobile devices.

As things stand today, ad blocking may even be becoming less of a headache for the ad industry. The leading blocker, AdBlockPlus, now permits ads in formats it calls “acceptable,” and takes money from companies including Google, Amazon, and Microsoft to get their “acceptable” ads whitelisted. PageFair’s report notes that ad blocking is essentially nonexistent on mobile devices at present; that’s where Web usage and ad spending is growing fastest. Lastly, companies that pay for ads are coming to prefer formats such as “native ads”–promotional content that gets mixed in with editorial content–and sponsored content, neither of which are targeted by ad blockers.