In a Medium article titled How to Make $80,000 Per Month On the Apple App Store, Johnny Lin uncovers a scamming trend in which apps advertising fake services are making thousands of dollars a month from in-app purchases. The practice works by manipulating search ads to promote dubious apps in the App Store and then preys on unsuspecting users via the in-app purchase mechanism. MacRumors reports: "I scrolled down the list in the Productivity category and saw apps from well-known companies like Dropbox, Evernote, and Microsoft," said Lin. "That was to be expected. But what's this? The #10 Top Grossing Productivity app (as of June 7th, 2017) was an app called 'Mobile protection :Clean & Security VPN.' Given the terrible title of this app (inconsistent capitalization, misplaced colon, and grammatically nonsensical 'Clean & Security VPN?'), I was sure this was a bug in the rankings algorithm. So I check Sensor Tower for an estimate of the app's revenue, which showed ... $80,000 per month?? That couldn't possibly be right. Now I was really curious." To learn how this could be, Lin installed and ran the app, and was soon prompted to start a "free trial" for an "anti-virus scanner" (iOS does not need anti-virus software thanks to Apple's sandboxing rules for individual apps). Tapping on the trial offer then threw up a Touch ID authentication prompt containing the text "You will pay $99.99 for a 7-day subscription starting Jun 9, 2017." Lin was one touch away from paying $400 a month for a non-existent service offered by a scammer. Lin dug deeper and found several other similar apps making money off the same scam, suggesting a wider disturbing trend, with scam apps regularly showing up in the App Store's top grossing lists.