I read that after the Arab conquest of Persia, Egypt, the Levant, and Central Asia, Islam spread first in the Cities and among urban professions like Artisans, metal workers, traders, merchants. Islam was adopted much later in the countryside and among rural peasants and pastoralists. The gap could be as much as 200 years, in the case of Iran and Egypt.
Any reason why this might be so ? Even in India, Islam seems to be disproportionately represented among Artisans such as Weavers, Tailors, Metal workers, blacksmiths etc. Any way that Islam was propagated that made it especially attractive to the artisanal professions ?
I would say that this idea comes from two important facets of the birth of Islam: first Muhammad's marriage to Khadija and then the Hajj. Next, the imortance of nomadic tribes and the Indian Ocean trade network spell out the directions and people that adopted Islam. However, withoht context, it can be argued that Islam first spread outaide the Levant militarily through the conquest of the Rashidun, Mu'awila's exploits, and the Abbasids. Later, Mongol Turks would help in bringing Islam further east. This is based off of A Concise History of the Middle East 9th Edition.
Muhammad had always been close to the Ka'aba, sacred before even Islam. His clan, the Hashem (?), cleaned the area and made connections.
Khadija, a widow, allowed Muhammad the start-up capital to travel. Khadija, daughter of a prominent Qurayshi merchant and widowed twice in previous marriages to merchants, had at this point certainly acquired a certain acumen for the field.as well as family connections. Her caravan was said to be the largest, spreading from Syria to Yemen. This trade network establisbed by the Qurayshi would be the route for spread of goods (and ideas, e.g., Islam). And in the Qu'ran, rights for widows and orphans were codified, so perhaps Khadija pulled off another brilliant deal. Pure speculation, no hadith about this.
The pilgrimage to Mecca would solidify the religious pressure emanating from Mecca. Yearly, believers were supposed to make the hajj to Mecca, following these routes. Merchants and artisans who frequented these routes would exaggerate this religious pressure by knowing what a large market Mecca had become, connecting artisans in nearby settlements to the local religious center that promised profits each year.
All supply chains may not have led to Mecca, but they made a pitstop there. Indian Ocean trade connected East Africa to Malaysia, and made a pit stop in Mecca. The heavy trade based on predictable weather allowed for continuous commerce throughout south Asia. Berbers in North Africa helped to spread Islam westward i to North Africa. As well, these were the first people to traverse the Sahara, which lead sto the stark difference today between a northern Islamic Africa and a Southern, predominantly Christian Africa. Note that in these exampkes, the people traversing the routes would.need reason to do so: economic or poltical. If not for conquest, for trade.
As for Asia, the Abbasids moved the capital to Baghdad, which was later sacked by the Mongols. The Il-khanate adopted Islam and spread it through its nomadic ways, and this is the most relevant example of the common citizen spreading Islam. However, the militaristic and hierarchical nature of Ghenghis Khan's sons shoukd not be forgotten. Nor should their spread of technology, like gunpowder from Yuan China. This spread even to Mughal India and later Europe. The adoption of other cultures intot he Mongol fold was paramount in concreting Islam through central Asia, getting as close to Europe as the Ottoman Empire by 1453.
Concessions:
The rapid advancement of Islam spread through North Africa and east towards Sassanid Persia. This would take on a different pattern of religious spread.
My teacher and the text described Islam as a religion 'made for the Arabs' and their economy. The book's author did not grow up in a Muslim community, nor did I, so their answer may be quite different. This is from an outside, scholarly perspective.