It wasn't actually announced at Apple's Worldwide Developers Conference (WWDC), but now it's everywhere: Apple plans to introduce an ad-blocking feature to the Safari mobile browser for iOS 9.

This is one of those moves that seems like, and perhaps is, a boon for users who are sick of slow-loading Web pages gummed up with commercials. There's a lot more to it than that, though. In the end, the ultimate beneficiary of this move is, of course, Apple.

Filtering out advertisements on a Web page is nothing new, at least on desktop browsers. Pretty much from the first time a browser supported an extension, there's been software that could kill the ads. AdBlock and Adblock Plus (ABP) (which are not related, despite the names) are arguably the two most popular. Both cover a wide swath of the browsers available: Firefox, Chrome, Internet Explorer, Opera, and yes, Apple's Safari. For Chrome alone, AdBlock is the most popular extension of all time, clocking in at 40 million users as of July 2014.

What these add-ons do in the browser is simple: they block HTTP and HTTPS requests based on the source address. They keep a running list of addresses of known advertisers, and can make sure that the banners and bugs from those ad networks don't show. It's pretty simple. They also can block extra things like Flash, so you don't get auto-playing animated ads using a different protocol. (It's worth noting here that Apple iOS has never supported Adobe's Flash. Steve Jobs hated it, which contributed a lot to video on the Web moving away from Flash support.)

So why not use it? Blocking ads on our site, for example, directly impacts the bottom line—and puts our site, our staff, and our future at risk. The same goes for thousands of sites, including big names like The New York Times and Fox News. These large outlets have a huge audience, yet still make a pittance online, so imagine the outcome for a bunch of smaller, online-only venues.

Still, ad-blocking has largely been relegated to the desktop. Moving ad-blocking into mobile creates a new wrinkle.

ABP actually introduced a beta recently of a mobile browser for Android, and had one in the works for iOS. Naturally, this news from Apple has ABP worried.

According to NiemanLab, Apple's developer docs say that "Content Blocking gives your extensions a fast and efficient way to block cookies, images, resources, pop-ups, and other content." Any actual ad-blocking will require software to interact with the Safari browser using an easy-to-parse-even-by-humans JSON (JavaScript Object Notation) file. ABP could potentially utilize it, but the chances are slim Apple will make it that easy.

Also, it might not be worth it to APB. No one makes money on add-ons for mobile browsers, especially Safari. But at least it used to be free to develop them. Now, Apple is going to charge extension developers $99 a year to get access to post the add-ons in the online gallery where most users find them. (This goes for the desktop and mobile Safari.)

So, publishers are hurt by this. Developers (at least a couple) are probably hurt by this. And maybe most of all, the advertisers are hurt by this—which is probably the point.

The No. 1 advertiser on the Internet is Google. Ads are where Google makes 90 percent of its substantial revenue, though CNN Money noted in January that Google's online advertising isn't exactly growing. Facebook, Microsoft, and other Apple rivals also have online ad networks that will be impacted.

Related iOS 9 to Support Ad Blocking on Safari

Who won't get screwed by mobile Safari's content blocking? Apple's iAds. That's because Apple doesn't do ads for the browser—it does them in iOS apps. Those ads will never, ever be blockable. With the closed system that is iOS, any app that would try 1) wouldn't work because they wouldn't be targetable with JSON files or via protocols like HTTP, and 2) if it did work, Apple would ban it.

No one in the world really loves the advertising model. It's frustrating at best, infuriating at worst. Web pages with auto-loading video ads, multiple ads for the same company, giant above-the-fold commercials pushing the content you want down—they're all detestable. But no one has come up with anything better yet. It's certainly not the subscription model that everyone hates and finds a workaround for. In fact, it's possible that Content Blocking Safari Extensions could even hurt that, as it can selectively block cookies that are used by many publications to track usage.

With this move, users will eventually wonder why their favorite website died before finding another set of content to plunder. But more specifically, it will help Apple get a complete and thorough stranglehold on the ads within iOS.

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