Adding your skills in your profile is critically important. We are different from all others because we are a competency-based platform. Your competency!
If you add your skills you will be able to compare them with the ones of other applicants or users. You could compare them between the applicants in one particular job or you could compare your self with the entire market.
Remember, your name will be never disclosed to another user unless you do not explicitly set this from your account management. That is why you will not see the names of other candidates or users unless they want this.
You can add your skills when you add initially your experience, education or certification in your profile. Or you can edit your items in the profile later and add more skills.