Mobile ad blocking is still relatively uncommon in the U.S.

But it's wildly popular in Asia and the Pacific.

Out of 1.9 billion smartphone users on the planet, about 419 million -- or 22 percent -- of them use mobile ad blocking tools, a new study from PageFair has found. While ad blocking has barely caught on in the United States, more than a third of all the smartphone users in the Asia-Pacific region use an app or browser to stop advertisements from reaching their phones.

55 percent of that global smartphone userbase lives in the Asia-Pacific region, NiemanLab notes, but it makes up 93 percent of the people who use ad blocking services. According to PageFair's head of ecosystem Johnny Ryan, slower devices and expensive mobile data are to blame for the sudden surge in popularity in places like China, India, Indonesia and Pakistan. By comparison, slightly more than two percent of smartphone users in the U.S. use ad blocking apps like Brave or Opera on their phones.

Given this popularity in Asia, it should be of little surprise that four out of the top five ad blocking apps are variations of Alibaba's UC Browser. (Although PageFair's report notes that lead might be shaken up by ASUS' plan to ship phones with built-in ad blocking.) Now that Google has loosened restrictions around ad blocking on Android, the coveted fifth-place spot goes to the simply named "Adblock Browser for Android."