This is the short version of why Islam is spreading so fast. You can click here to read the detailed version but be prepared to be mesmerized. It is written for the layman but those who really want to know why things grow or those with business perspective, have rated as one of the best reads.
Islam is not only a region but a beautiful way of living life but the biggest reasons why people are converting to Islam is :
How Muslims treat those around them and the way they look after them builds a superior bond. In Islam this superior bond is called Ikhlas (sincerity).
The role of Ikhlas (sincerity) in spreading Islam
The biggest reason Islam has spread around the world is not because others see you pray five times a day, or hear you read the beautiful Quran. The biggest reason for the spread of Islam is the Ikhlas of the Muslims.
Being fully sincere, humble and looking out for the best interest of those around you. When others see how nice you are, how honest you are and your sincerity demands nothing in return, that is when someone says,
I want this;
and If this is what Islam teaches,
I want to be a Muslim;
If this is how Muslims are,
I stand in front of all the people present today and I say to the whole world:
“Ash-hadu an laa ilaaha illaallaah, wa ash-hadu anna Muhammadan-ar-rasool ullaah” (in Arabic)
“I bear witness that there is no God worthy to be worshiped but Allah, and I bear witness that Muhammad (PBUH) is the Messenger of Allah.” (Translation in English)