I wouldn't compare it to being a model because acting requires actual talent.
I know this is an arrogant statement to make, but there have been so many model-turned-actors lately and at least 80% of them don't have the chops to back it up. People have this backward notion that being an actor is the same as being a celebrity, and tons of untalented idiots are getting chances simply because of their looks (e.g half of The CW cast), when in reality you have to study to improve your craft. When talented people like Mads get good opportunities is always a pleasure to watch.