Williams talks about the change in a blog post: “While the board of directors and the company have nothing but praise for where Jack has taken us, we also agree that the best way forward is for Jack to step into the role Chairman, and for me to become CEO. Jack will remain on the board and be closely consulted for all strategic decisions”
Williams also praises Dorsey for growing the company to its current state, noting that the original idea for Twitter was his.
Twitter came at a time when the company’s first product, Odeo (a podcast service), was sort of going sideways, and was eventually sold off in mid 2007. Twitter quite literally saved the day for the company.
But Twitter has had more than its fair share of operational issues. And competitors like FriendFeed have evolved their services much more quickly that Twitter has been able to do.