You mentioned EventVue's excellent post-mortem already. But for anyone thinking of building a startup in that space, Josh Fraser (EventVue's co-founder)'s follow-up post is also a mandatory read: http://www.onlineaspect.com/2010/10/26/a-few-words-about-eve... - since he posted that follow-up on his own blog, it would be worth linking both in the article.

And if anyone is thinking of building something in the event space, read both of these posts. And then read them again. Josh is 100% spot-on. Absolutely nothing has changed in this industry since he wrote this (the events industry moves at a glacial pace).

We pulled the pin much earlier than most of your list, but if it helps add to the knowledge base: http://everydaydreamholiday.com/2013/03/25/dont-dream-its-ov...

Most of Marc Barros' blog is a post-mortem of Contour: http://marcbarros.com