Twitter is such an unlikely success. It&#x27;s a product that few understand, and even when you do, it&#x27;s hard to explain it. The functionality is dead-simple. But, at scale, its effect is magical.<p>I think closing down the service to developers was its pivotal mistake. The possibilities were endless, and could have solidified Twitter as the &quot;utility&quot; Topolosky speaks of...but they got greedy.