Studies consistently show that insider referrals far outpace online applications in helping candidates secure interviews and jobs. This outcome relates heavily to credibility. It is assumed that an inside referral is made by an employee who is willing to risk their reputation by recommending you. An online applicant with no connections to the business is a complete unknown.
This, of course, is where the hard work associated with networking can play out to your advantage. Creating all those connections that allow others to understand your value can pay off big time "behind the scenes." A trusted opinion can outweigh a high-powered resume in certain circumstances and certainly can help to substantiate its claims. And this is a major reason why networking is such a critical component of the job search. In today's highly documented world, you will still likely be required to apply online to comply with HR recruitment and hiring policies, but will be far less likely to languish in the black hole of applicant tracking systems.