What were some of the reasons that led to the rapid expansion of Buddhism in India and other parts of the world?

Some of the different reasons that led to the expansion of Buddhism are:

1. The ideology of Buddhism was appealing to the wide sections of the Indian society as large sections were a sufferer of the radical approach of the caste system.
2. Large number of people were dissatisfied with the religious practices going around them and the social changes in the society.
3. The ideology of Buddhism gave importance to the conduct and values of the person rather than claims of superiority based on birth.
4. The Buddhist ideology emphasised the fellow feeling and compassion for the younger and weaker sections of the society.
5. The liberal ideology of Buddhism became the leading cause of its popularity among the weaker sections of the society.