“I can think of nothing that has done more harm to the Internet than ad tech,” says Bob Hoffman, a veteran ad executive, industry critic, and author of the blog the Ad Contrarian. “It interferes with everything we try to do on the Web. It has cheapened and debased advertising and spawned criminal empires.” Most ridiculous of all, he adds, is that advertisers are further away than ever from solving the old which-part-of-my-budget-is-working problem. “Nobody knows the exact number,” Hoffman says, “but probably about 50 percent of what you’re spending online is being stolen from you.”
Apple allow ad blockers in iOS 9 is the outside context problem that the advertising industry has been in dire need of for quite a while.