If you concentrate only on what you can build, you end up making something that nobody actually wants, even if you're passionate about it. If you concentrate only on what you can sell, you can promise things you can't build. If you build what you can sell but aren't passionate about, you end up working hard to build mediocrity. But in the center, that sweet spot, is a vision rooted in reality – a vision with a real possibility of becoming something great."
– Jeff Sutherland