Have you ever accepted a promotion or a new role in spite of knowing that one of your colleagues has already refused it?
How does it feel to be the second option? Personally, I never liked the idea of being a backup choice especially for a career growth role within my own organization. I felt it was an 'insult' to fill a role for which 'they' originally had somebody else in mind. It felt even worse to know that that first choice had refused that role.
If you are in a similar situation would you grab the growth that has come your way? Or, you are the "Curious George" types and ask why did the other person refuse the role or 'why' you weren't the first choice? The first time I got an overseas opportunity I knew I wasn't the first choice. But, I was excited and accepted it immediately and within 15 days was in a new country.
A few months later I asked my peer who had originally declined the role for the reason. He smiled and said, "the salary was lower than my expectations, but HR said you had accepted the same offer". That was the only day I felt bad about being the second choice :) John Travolta refused to do Forest Gump and Hrithik was the first choice for Amir Khan's role in Dil Chahta Hai. Does it matter if you are the first or the backup?