> An example would be an app where each user account is storing and accessing only their own data. E.g. something like a todo list, or a note-taking app, wou

> An example would be an app where each user account is storing and accessing only their own data. E.g. something like a todo list, or a note-taking app, would be examples where Mongo may be beneficial to use. You dont need mongo db to store todo list datas. My opinion is , in some plateforms, like nodejs,where orms and rdbms drivers are not mature , it's quicker to stuff your app with a mongodb rather than a relational database, because they both use javascript and json data structures. But does mongo db scales easier than a mysql database ? is it even easier to manage ? i dont think so.