I think the main thing is that Katrina admits (unlike others) that she has only had one film so far to demonstrate her acting abilities - that film being Namaste London.
She's handling her career really well, and has picked up very quickly on the fact that she initially pulls audiences in because of her beauty, glamour factor and justice to the little typical 'actress' role she is given. Even for Yuvvraaj, she said that shes only accepted the film so that she can say that she has worked with Ghai.
I think in the past and presently shes concentrating on creating a brand value for herself by being associated with good commerical films....once she's done with this, i guess she will continue to choose more serious roles like Namaste London, Rajnithi.
I don't think Salman has played a part in her success, since they never flaunted their relationship. Whether someone is a success is down to the audience, not a celebs partner (although it can have negative and positive influences).
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