Re: Blame FOSS
It’s not FOSS, although FOSS has done a lot to encourage “free as in beer” software. The rise of adware on mobile is down to decisions Apple made about pricing, and Google’ day-job as an advertising broker.
What it is the the App Store pricing model. The first, obvious push-factor is the high commission. If I published an app and sell it for $10 a pop, Apple took $3. So, whatever price I set to meet my own cost of living, I had to raise it to account for Apple’s markup, and the higher pricing means fewer customers and possibly less revenue overall. On the other hand, if I gave the app for free and used in-app advertising, then I save that 30% commission, get a much larger pool of users, and chances are I’ll earn more.. and it’s recurring revenue.
The second push factor is less obvious unless you were actually an iOS app developer, and that is that for most of the App Store’s history, version upgrades were free and automatic, regardless of scale. You write an app in 2008, a lot of people download it, you get money, great. Then it needs to be updated for the next iOS SDK (remember, you can‘t submit apps on very old SDKs - Apple pushes the burden of app compatibility onto developers), so you do that: time spent, but happy users, and you pick up a couple of new sales, so great. Your app starts falling down the sales charts? The best way to gain visibility again was to submit an updated version, so you add features and post again, and get a few more sales. The future looks golden...
But fast forward a few years, and your app, that has become your full-time job, and is unrecognisably improved since its first version, is just not paying anymore. The app market is now stagnant - anyone who wanted your app has bought it, and you realise you’ve been trapped into doing free maintenance programming in exchange for a handful of new sales each year. Meanwhile, your electrical supplier doesn’t take “#1 iPhone Banjo App” as payment for bills. So... there’s now a “Free” version of the app. With ads. Ads pay you every month.
(To revive a bit of suppressed history: Apple also tried to get onto the in-app ads bandwagon with its “iAds” product. You never hear about iAds anymore, and Apple now pretends that it was far too moral to ever use user information to target advertising, but if iAds had got any traction at all when launched—it did not—Apple would be all for “responsible advertising”)
On Android, ad-supported was pushed as an equal business model to paid from day one, because Google doesn’t care if it takes its cut from a purchase fee, or via an ad-placement fee.