Why did Buddhism spread over large areas but Jainism did not?

Buddhism and Jainism are related religions that started in India in ancient times. However, Buddhism spread to become a world religion, while Jainism, though still in existence, did not spread to the same extent.
One limiting factor for Jainism is that it requires adherents to be vegetarians, while Buddhism does not make the same requirements of followers. Therefore, the dietary restrictions in Jainism make it more difficult to follow. In addition, Buddhist monks are allowed to remain in one place, while monks in Jainism must be peripatetic and travel from place to place, making it more difficult to be a monk in this tradition. As the source below states, Buddhist missionaries traveled abroad to spread their beliefs, but this is not true of Jainism.
Finally, Buddhism received the support of world leaders like Ashoka, a Mauryan emperor. In spreading his empire, he also facilitated the spread of Buddhism. The support of political leaders such as Ashoka was critical to the dissemination of Buddhism, and Jainism did not have this type of political support.
http://www3.northern.edu/marmorsa/WorldReligionsBuddhism.htm