By land and sea they brought people, goods, religions, and diseases.  It seems like the movement of goods, by trade along the land and maritime silk road during the period between 500-1500 A.D., was more influential in its effect on cultures than the movement of peoples.  The propagation of Indian religions like Buddhism by the traders, along with their wares for sale, forever altered the landscape of these vast areas along this trade route. I think that it was more of a velvet revolution of philosophical ideas shared by this cultural elite of traders,  as opposed to the later missionary style of hammer and nail theology. What I mean by that is, I don't get the sense that anybody was proselytizing, as much as sharing ideas across the cultural divide.  The traders seem like an elite clique that had an advantage over their other more stay at home brethren, they got to live the exciting life of new adventures in exotic locales. This brotherhood of trade was a perfect breeding ground for the exchange of ideas. It also makes sense that those along the trade routes would want to show solidarity with their peers, and honor them by adopting, what would probably seem now like the popular new in thing, Buddhism.  These common beliefs among people spread far and wide, and the subsequent building of temples, monasteries, and icons must have further cemented these relationships and bonds of the traders.  Even today it sounds exciting and exotic to have lived during that time and have been a silk road trader/traveler, being at the forefront of discovering new goods, new ideas, new lands, and new peoples.  When I think of the scope of World trade today in the modern world, with airplanes, ships, trains, and trucks, other than the speed of travel, probably not that much has changed.  We are still seeing the propagation of new goods, new ideas, and new diseases spread around the world.  Maybe this is why when we travel we like to shop so much, this is our chance to experience the trade of goods and ideas with foreign cultures and peoples, even if the road is short, the difference can be quite profound.