When I was buying my last car, I went online for reviews to see what owners thought of the make and model before ever contacting the dealer. People gave me a lot of great information that allowed me to feel comfortable with my choice of cars and negotiate price. After all, people are very generous online when it comes to sharing information. This is also true with books, music and scores of other things, including your expertise.

Recommendations, skills and endorsements are a way of demonstrating social proof on LinkedIn for you and your abilities. Recommendations are long-form testimonials that people provide about you and your work. Because LinkedIn allows you to screen these before approving them for your profile page, no bad recommendations need to appear there. However, an organization can discern what it wants by looking at them — and they do look at them.

Imagine you were trying to hire someone and you saw that a candidate had been endorsed for a particular skill four times. Would you be as impressed with them as you might be with someone who is endorsed for it 40 times? How about 140 times? How about 440 times? There is an impact that people receive with skills and endorsements on LinkedIn and texture provided through recommendations.

Since companies scan LinkedIn profiles for congruence between your resume and profile, they notice recommendations and check whether you have been endorsed repeatedly for the skills and experiences that you claim to have on your resume. After all, they notice that you might have relatively few endorsements for a particular skill or experience that is required for their position and that you have received many, many more for a different skill. That sends a clear signal to them: where your expertise really lies. Your LinkedIn profile needs to demonstrate congruence with what you are claiming to be an expert on when applying for a position.

In addition, if you are being “hunted” by a firm for a role, recommendations, skills and endorsements clearly communicate whether you have simply dabbled with something or you’re an expert at it.

So how do you build up your recommendations, skills and endorsements?

This is something that you should be doing throughout your career. You need to ask people to write testimonials for you. Every time you complete work of significance, ask for a recommendation from those who you positively benefited. Recommend them too. Reciprocity on LinkedIn is always appreciated.