Why is it that some ideas or products become unusually successful and get adopted widely while others don't? This question has been puzzling many social scientists, economists, politicians and educators for a long time. Knowing the answer to this question can help deliberately start such successful cascades. Many theories have been introduced in this topic by economists and social scientists and these theories have been backed by small numbers of case studies. In this paper, we will focus on the popular theories introduced in "The Tipping Point" by Malcolm Gladwell. The basic idea is the crucial effect of three types of "fascinating" people that the author calls mavens, connectors and salesmen on the effectiveness of a cascade. Those people are claimed to "play a critical role in the word-of-mouth epidemics that dictate our tastes, trends and fashions". In this work, we investigate existence of mavens, connectors and salesmen in the blogosphere. We formally define what it means to be a maven, connector or a salesman and study their possible effect on the success of cascades in the blogosphere. We also study a fourth type of interesting actor that we call translator, an actor that acts as a bridge between different interest groups and communities. We observe that these four types of important players do in fact exist in the blogosphere and they have high correlation with successful cascades. More interestingly, we show that the cascades where these actors act as intermediaries rather than initiators are more likely to reach a larger size.