Jai Sri Ganesha,
Greet the lotus feet of Lord Shiva that worshipped by all gods and celestials including Lord Vishnu for being a prime deity in truth with sole cause of this universe with spirit and matter to relate the life of animate inanimate,
Lord Shiva the architect of life in the universe with socio cultural in truth with eternal cult of inherent self, devotees franchise their truth to make fair oblations to greet lord,
The whole universe is cosmic body of Lord Shiva and Shivling represent this reality, Know this Shivling with embodiment of eternal fire that impart pace to the universe on the scale ot time,
Truth of Lord is abode of all gods, hence oblation for any specific god could also be made on Shivlingam and that reached to respective deity much faster than any money transfer system available on the planet,
Jai Mahadev