“any updates beginning with @username (that are not explicitly created by clicking on the reply icon) will be seen by everyone following that account.”
Twitter Blog: We Learned A Lot
Yeah, because everyone wants to ignore the ‘reply’ button, and it’s so not useful at all for followers to be able to easily find the tweet to which their idol is replying. Obviously.
If the prior implementation didn’t scale, then it didn’t scale. Write a new one. And if that new one takes a week to implement, bring back the old way while you write the better one.
