After all, promoting bitcoin can be done in various ways. Exchanges play an important role in gaining more interest in trade, while others can promote their use cases such as adopting bitcoin as a means of payment at their business. Someone wearing a shirt with the bitcoin logo is also promoting bitcoin, that is because they allow others to become aware of bitcoin's existence.
Promoting bitcoin with its main goal is the best way. Bitcoin was created for the transaction. Borderless transaction with bitcoin is fast, hassle-free and cheap. Anyone can make worldwide big transactions with bitcoin for less fee and in no time compared to other payment types. It is also effortless, if you use other third-party payment gate-way to send money from one country to another and the amount is big you have to go through some serious verification. But with bitcoin you don't need to pass any verification or longer waiting time.