I'd like to answer this. You're separating layout logic/codes to client side. Not only that but your server side code is now basically a web service, usually

I'd like to answer this. You're separating layout logic/codes to client side. Not only that but your server side code is now basically a web service, usually Restful. So it's real slim and all it does is serve data. And your client side will be the one responsible for rendering the data. This also may forces your layout code to be front end, which people can steal, but it put more emphasis on the value of your data. Then again you can steal webpage design css/html all the time... likewise with javascript anyway. And another reason for using client side MVC is because they want their web application to act like an application and less of a webpage so you'll hear the term single page application a lot. It's a whole a trend, they created AJAX so it's less like a webpage more like a web application. Of course it depends on your project/website and it requirement and if it's more like an application or more of a website. There are some drawbacks to this, SEO namely for angular but you can have work around like phantomjs. Not so much for ember.js (I'm about to learn ember soon...).