Keeping Your Maiden Name Vs. Taking Your Husband’s Name

I was recently talking to a friend who is engaged to be married and she mentioned that she was going to keep maiden.  I was kind of shocked.  I've heard of people doing that, but I've never really known anyone to do this.  So how common is keeping your maiden name?

A few years ago when Kim Kardashian married Kris Humphries, she chose not to take his name.  This actually got me thinking about marriage and last names.  Why wouldn't wives want the same last name as their husband?  That is what I was taught.  You marry and become part of his family.

It is kind of like a team.  You and your husband become a team so you need the same team name.  And on top of that, wouldn't you want the same last name as your children?  You'll eventually have to explain to your kids why you have different last names.

I understand celebrities who have built an empire around their last names, like Kim K.  But why wouldn't other women want a family name?  Maybe I am old fashion, but I feel like you aren't putting your whole self into the marriage.  And if you don't put your whole self into your marriage, will it really work?

As much as I love my maiden name, I would never want to be different from my family.  To me that means you get married and take your husband's last name.  The last thing I'd want is for my husband to feel that I wasn't fully committed to our marriage.

How common is keeping your maiden name when you get married and what is the purpose?