When I first heard of 3D printing, I used it as an example that "even companies like Lego are severly threatened by digitization" - since building "bricks that fit on one another on demand" seemed like the easiest thing to do with a 3D printer. Ever since, 3D printing moved on to producing prosthesis, houses and a lot more serious stuff than Lego bricks. And Lego reacted, too. With a lot of innovation. One of these things is an app where you can actually build a virtual Lego Empire but based on houses that you physically build with special bricks. Great idea.