History - India has a long history of cultural intercourse with many regions of the world. Its cultural influence has spread through the philosophy of religions like Jainism, Sikhism, Hinduism and Buddhism (particularly in East and SE Asia). Many foreign religions - Christianity, Islam, Judaism, Zoroastrianism, Bahá'í Faith - have found home and followers in India. India has no history of imperialism. Indian culture has always spread naturally or through widespread emigration to foreign lands.
Bollywood - India's film industry, often known as "Bollywood", produces more feature films than any other (though not all of great quality) . In a year, it sold 3.6 billion tickets, more than any other film industry in the world ( In comparison, Hollywood sold 2.6 billion tickets in a year) .
Unity in Diversity of world view - The scale of multi-ethnic, multi-lingual, multi-religious people trying to cohabitate here is unparalleled in the world. The subcontinent's long and diverse history has given it a unique eclectic culture, claimed to be one of its great intangible assets. It is also often associated with spirituality. India's diversity forces it to either evolve strong foundations of tolerance and survive, or face break-up. The Indian public is now also accepting western influences in their society & media - and what is emerging is a confluence of its past local culture with the new western culture ("Social Glocalisation"). For some futuristic social thinkers, the miscegenation of diverse ancient culture with modernity, spirituality with science/technology, eastern with western world-view is potentially making India a social laboratory for the evolution of futuristic global-unity consciousness . If, and only if, everything evolves right, then South Asia could emerge as a soft super-power, by being the biggest melting pot of human ethnicities, languages, cultures, religions, ideologies & world view.