Simhachalam is the second-largest after Tirumala in Andhra Pradesh in terms of income earned; as of 2013, the earnings stood at 60 crores (600 million). It is the first temple in the north coastal region of Andhra Pradesh and second in the entire state (after the Satyanarayana temple in Annavaram) to follow the cashless system. Point of sale systems. provided by the State Bank of India and Andhra Bank, are used for accepting donations and gifts from devotees. Simhachalam temple found many literary references and lyrical works dedicated by anonymous writers; some of the latter are preserved in the Government Oriental Manuscripts Library, Chennai. The earliest known literary mention of the temple is found in "Lakshmi Narasimhapurana" written by Telugu poet Yerrapragada. He mentioned it as a place of pilgrimage visited by a sage on a holy tour. But Yerrapragada did not describe the temple as the work was focused on Ahobilam temple. Srinatha described the "Simhadri Thirunaal" event, a festive gathering at the temple. He described the various classes of ladies assembled at the gathering in his "Chatuvulu" (extempore poems). Krishnamacharyulu wrote devotional "vachanas" (prose) in praise of Varaha Narasimha of Simhachalam. Written in churnika style, they are known as "Simhagiri Vachanas" and "Simhagiri Narahari Vachanas". He was the first Telugu poet to use "bhakti" (devotion) in Telugu literature and was succeeded by Annamacharya, Kancherla Gopanna and Tyagaraja. "Simhagiri Vachanas" had features of the Shatakam-style of poetry. It is believed that Krishnamacharyulu was inspired by Ramanuja's "Gadyatrayam" and opted for prose to reach the ordinary people. Krishnamacharyulu wrote 400,000 "vachanas" on copper plates of which 75 are available after he left for Srirangam. The "vachanas" begin with an invocation to the deity. "Simhagiri Vachanas" are recited by the local villagers near Simhachalam during special occasions. These "vachanas" also inspired many other poets to compose similar devotional prose including Pothana and Srinatha; the latter introduced 12 laudatory pieces showing Krishnamacharyulu's impact in his works "Bhimeswara Purana" and "Kasikandham".