Namasankeerthanam has become important when there was restriction in practising Hinduism post invasion Era .. and Sri Sri Krishnapremi Anna used to mention that " Ra" from " Om Namo Narayanaya " was taken and " Ma " from " Om Namachivaya " was taken and the word RAMA gained significance in South too !!
Like they say " Jayaramjiki jai" - in South also RA-MA chanting gained momentum .. after the Trio !!
King Sarfoji/s also patronised them and it is believed Bodrendra Swami is in Jeeva Samadhi and even today RAM chanting is audible to the selected ones who are previleged to stay there overnite.
Like wise Dakshina Pandaripuram is gaining popularity thanks to Harikrishna Dikshidhar.
You will be surprised, some of the books of Kudanthai N. Sethuraman - re Cholas - were published from Govindapuram !!