In the past, I’ve made a couple of projects just for fun, but now I’m thinking on how to make my next one kind of profitable, I know that there are different factors that can make it work as I expect or not, so I don't intent to gain a lot of money on my first try, but I would like to know if in your experience a web app can be fully maintained (at least) based on the ads income with a platform like Google Adsense?