Merchants spread Islam through ways of communication. A Non-Muslim merchant would meet a Muslim merchant and learn about his culture, traditions, and religions. On come occasions, this would result in conversion due to the perceived merits of Islam.
Islam did not spread the same way throughout all of Africa. In North Africa, Islam spread by conquest. In West Africa and along the Indian Ocean, Islam spread by contact between Muslim merchants and local Non-Muslims.
How did the Beduins help expand Islam
ISIS
Typically, Arab merchants spread goods from place to place. (That's what merchants do.) However, merchants also facilitate cultural diffusion which allows for religions to move between countries. It was through Arab merchants that Islam disseminated through West Africa, East Africa, and much of Indonesia.
I've heard that merchants and business people's kind of habits, practices and moral values have caused them to turn into Islam. That's a good example however to refute the slander which claims that Islam had spread by sword.
muslim merchants travild sending religion with them
Merchants and teachers help spread Buddism.
Merchants and teachers help spread Buddism.
Muslim merchants set up trading posts throughout southeast Asia and taught Islam to people there.
passing on their opinions when they travelled
Islam first spread along TRADE ROUTES since merchants could often bring the religion to places too far away to effectively conquer.
Ben Brierley raped Allah :'D