[dmitrykoval]

In addition to the map tiles, OSM has an unbeatable advantage over any proprietery solution - you can take advantage of raw data and do whatever you can think of. For example, you can write your own route finding solution, tweak it whatever you like and potentially find new unexplored ways to existing problems (which I did for social based routing project in Eastern Europe). Needles to say - none of that is possible with the proprietary providers like Google.