That only works as long as your addressable market is growing. You see it on app stores. Many early Indy developers were making money selling 0.99 apps where you paid once and got free upgrades forever. That was fine when the iOS market was doubling every year. Now, lack of upgrade pricing is forcing app makers to either make money from ads or subscription pricing.
Back in the day Angry Birds cost $0.99 with no ads and you could use it forever. I downloaded it again recently just for nostalgia purposes and there is no option to get rid of ads. EA had a version of Tetris that cost $0.99 that was released during the 3.5” era was never upgraded, but stayed in the App Store until iOS didn’t support 32 bit apps. They replaced it with an ad supported version.
What is wrong with not continuing to make money on something?
Let’s say you spend $100,000 to make a piece of software, you sell it to 150,000 people at a $1 a piece... and that’s it. People don’t keep paying for it, but you also don’t keep investing in it. You move on to making something new.
I don’t like this idea that you need to keep making money off something that you made years ago.
It would be fine to move on but in the case of Angry Birds. Wouldn’t the company get a bad reputation if they didn’t keep the game compatible between the 3-1/2 inch iPhone up to 5 and the iPhone 5? When a new version of iOS caused it to crash?
But more importantly, if you bought MS Office for a one time fee of $100 and the next month, Apple introduced a new form factor or new features and either MS didn’t support it all or forced you to pay the full retail price, would you be upset?
People buy apps and expect them to continue working when they upgrade their phone. What are you left with besides ads and subscriptions without upgrade pricing?
Yes, very true. That's the incentive for me, a hobbyist with very few customers, but when you've captured a lot of the market and your users never need to replace your product with a new one because it broke, you'll soon hit a wall.