Poor design = storing passwords in cleartext
Senseless acquisition = entering a fast-growing market like India by acquiring a 2nd or 3rd tier player like SoSasta.com(http://www.techinasia.com/groupon-india/). Instead, they should either have entered directly, or bought out a leading player.
Multiple u-turns in strategy = going from SoSasta.com to Crazeal.com to Groupon.in in the space of 2 years, without any traffic or revenue results to show for it.
I'll ignore your last question asking about my qualification to comment. Because it has no relevance at HN.