If they throw it out and it's great then they get accolades; if they throw it out and it's bad, they don't. If they polish it and see if it works based on real user feedback then they also don't but it took longer. Better to just throw everything at the wall the instant it has the potential to go viral and then move on if it doesn't.
Remember that Google operates at huge scale, so even something any other company would consider wildly successful (e.g. Reader) is a waste of resources for them. That means that if you're ramping up your product over the course of a year you're wasting time and money. Go big or go home.
Remember that Google operates at huge scale, so even something any other company would consider wildly successful (e.g. Reader) is a waste of resources for them. That means that if you're ramping up your product over the course of a year you're wasting time and money. Go big or go home.