One of our clients went with a card-based approach (http://purelyapp.com). The reasons were:

- People understand them. The separation and spacing lead to very little cognitive overhead.
- Perfect for responsive layouts, and translate easily to native mobile devices.
- Forces you to discriminate - you can't cram too much information in a card (at some point it ceases being a card), so it provides a nice constraint and keeps your product simpler.
- Easier to A/B test. Cards are a great example of what Andrew Chen has called an 'open system'. Many layouts are just loops of cards, which means making changes to a card object is trivial vs. changing the layout of a less modular, more structured page.

Hope that helps!

Yes, I've implemented the card based UI in a mobile app. In our particular case, cards work very well as we want the user to be forced to make a decision in the information we're presenting them but that kind of cognitive load is not something that all apps can or should be able to justify.

Implementing cards as a UX does force a lot of constraints if you're going to do it well but without knowing more about what you're designing, it's hard to give a helpful answer.

Happy to talk to you in a brief call and provide you some more contextually-relevant feedback.

What does a card really do?
- It helps clearly group information
- It helps group information with relevant tasks
- It can help to show quantity of information according to need
- It can help show other aspects of information normally not seen upfront

There are several ways to group information as per the need of the users and brand. Graphic designers and user experience designers have been grouping information as a part of their job.

In the recent times, a lot of people needed to group and categorise information. However, without the knowledge of Gestalt's Laws and training in graphic design, it is a guessing game for anyone. At that time, card based UIs came to rescue - they did the job perfectly - and looked good too!

So, if you and your designers have zero training in graphic design, and you have an information heavy website/application, card based UIs can be good.

And, one word of caution, group information that makes sense to users together (even if it comes from different database tables). Do not naturally group information that are columns in the same table in the database!