I generally hate them in consumer-targeted apps. Theoretically, there’s nothing wrong with the model. Devs have to keep the lights on, especially if there is a cloud service behind the app. It’s all about what pricing model they set. However, pricing is hard. A lot of companies really screw this up right at the start. I also think a lot of businesses cannot resist the temptation to boil the frog and ask for more and more over time, until their pricing is way out of alignment with value delivery.