śravaṇa-ādi-kriyā - the process of hearing, chanting and so forth; tāra - of that; svarūpa-lakṣaṇa - symptoms of the nature; taṭastha-lakṣaṇe - marginal symptoms; upajāya - awakens; prema-dhana - love of Godhead.

“The spiritual activities of hearing, chanting, remembering and so forth are the natural characteristics of devotional service. The marginal characteristic is that it awakens pure love for Kṛṣṇa.