Some substantial reasons why Salman won...
1. A very graceful dancer and does bollywood dancing very well
2. Creates great chemistry with girls as seen with Khushboo, Alisha, and also "Shree" (although she was ill)
3. Strong personality. I think this is one of Salman's most admirable traits. He is so modest yet confident. He doesn't brag in himself and even though he knows he is very popular, that "ghamand" or proudiness never comes across his face... To become a celebrity, that is a wonderful trai to have
4. Is able to appeal to the Indian audience emotionally. As many know, Indians are generally characterized as being emotional. It doesnt take long for an Indian to be swayed emotionally...
Now, how does Salman do that? Good question. He thanks "Allah" and his parents almost everytime. The way he went to his parents when he won was simply a wonderful moment. We Indians like it when celebrities (yes, I'm calling Salman a celebrity because he is worth it) respect our parents and have strong faith in God.
5. Yes, looks are important. This could be a reason why so many girls vote for him. But Bollywood is the place Salman is now heading where it is necessary to be good looking, which Salman has.
6. And lastly.... Luck plays a huge role. For example, he garnered top votes when he did not do as well during his last performances (his patriotic act and dance with Shree)
My personal opinion is that out of all the contestants, Salman will go very far, not because he won, but because he has a strong personality and large fan following. I adore his simplcity and modesty and also loved that he so graciously accepted his win. Many people like him a lot because of the way he presents himself, which is very imporant.
*Guys, I'm very happy for Salman even though I really wanted Jai to win since he is the true dancer. What I wrote is just how I feel about Salman's win and am not biased towards anyone. I don't want anyone saying, "Oh, so you have always been a Jai fan and suddenly you are favoring Salman because he won??" This is just an honest opinion of mine*