An example of rising to the stage of ecstatic love by executing the regulative principles of devotional service is given in the life story of Narada, which is described to Vyasadeva in Srimad-Bhagavatam. Narada tells there of his previous life and how he developed to the stage of ecstatic love. He was engaged in the service of great devotees and used to hear their talks and songs. Because he had the opportunity to hear these pastimes and songs of Krsna from the mouths of pure devotees, he became very attracted within his heart. Because he had become so eager to hear these topics, he gradually developed within himself an ecstatic love for Krsna. This ecstatic love is prior to the pure love of Krsna, because in the next verse Narada confirms that by the gradual process of hearing from the great sages he developed love of Godhead  

(N.O.D Chapter 17.)