Importance of LinkedIn Profile?

Anyone know how effective a very strong LinkedIn page paired with LinkedIn premium is towards getting job leads and interviews for non-entry level positions (particularly those in the 80-110K salary range)?

To be more specific, people who are looking in fields such as new product development at science companies, either business or technical and already have a strong resume and credentials. If it really does help, which portions are most important to getting to the top of the search results for recruiters? Do they search by keywords that can be found anywhere on the page or only those specific to endorsed skills, published papers, job titles, degrees etc?

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