The author is measuring largest cluster-size vs threads/button.
In any software, everything is going to be connected, otherwise there's unreachable code. So the largest cluster is always 100%, so I don't get why his argument about the sudden phase transition is relevant to software?
I think Twitter is moving towards advertising with their MoPub acquisition. Twitter has your identity and users have no expectation of privacy (unlike facebook or google), so people think that they have a unique advertising advantage.
I think the license restrictions on its firehose partners will become more strict as Twitter realizes it can go vertical and use the data itself to create platforms for social media analytics and advertising.