Not everyone may use this feature but for anyone who does can add their own Google Analytics code.
Adding Your Code to Your Theme
Log into your WordPress Admin area and go to the APPEARANCE >> THEME SETTINGS and then scroll down until you see the Google Analytics settings:
By default, this field is left blank so you will notice the above sample shows code. I did this for a demonstration of what the code will look like when you copy and paste it from the Google Analytics site. What happens is when you click SAVE, your code will be automatically entered into the source code of your web pages. To make sure, view the source code of any page and you should see it there.
Checking Google Analytics Results
You should check your statistics a day or two after you entered your code to make sure that its functioning properly. If so, you should see stats showing up, but if not, try adding your code manually to the footer.php file just before the closing </body> tag and then check it a day or two later again.