Ex-Groupon, before and after IPO. Groupon would make a great case study. The fundamental problem was that everyone knew "deal" websites would be a good business

Ex-Groupon, before and after IPO. Groupon would make a great case study. The fundamental problem was that everyone knew "deal" websites would be a good business, that it would be very winner-take-all because of customer attention and supply, but no one knew how big that industry would be. So lots of companies got into it, but no one knew ahead of time how much it was worth spending to win the fight.