This is a good summary: http://www.mathewingram.com/work/2015/04/30/twitters-multi-billion-dollar-mistake-happened-five-years-ago/ http://www.mathewingram.com/w

This is a good summary: http://www.mathewingram.com/work/2015/04/30/twitters-multi-billion-dollar-mistake-happened-five-years-ago/ http://www.mathewingram.com/work/2015/04/30/twitters-multi-b... and the HN discussion: https://news.ycombinator.com/item?id=9470312 https://news.ycombinator.com/item?id=9470312 TL;DR: Twitter was an open ecosystem with lots of partners and a thriving developer environment. They chose to stop all of that, end their developer relations, and ensure that Twitter Inc was the only way that anyone could Twitter. Now, that closed-off-ecosystem is making growth difficult.