What are the major factors of the rise of Islam during and after the life of Muhammad?

There are a number of factors that could help to account
for the rise of Islam in the time during and soon after the life of
Muhammad.

First, we have to assume that the content of the
religion itself had something to do with its spread.  The theology of the religion and
its emphasis on monotheism and community must have been appealing to people in the areas
that it came to dominate.

Second, the location of Saudi
Arabia was important.  This was a crossroads for trade.  Because of that, the ideas of
Islam could spread with traders and come to appeal to those in neighboring
areas.

Finally, the military prowess of the Muslim armies
had something to do with the spread of the faith.  The armies were able to conquer far
and wide and that enabled them to spread their religion to far off
areas.