When you visit a website and click on a link to get information, do you expect the information to be free and with no registration requirement?
Almost always the answer is 'yes'.
Yet, for the marketer, giving away free content without getting a contact is not a great way to collect leads.
So what's the answer?
Maybe an option is to 'step' the offer. In other words, you can offer a teaser, such as an excerpt of a white paper. And for this, no registration is required.
Then, once your site visitors become intrigued by the free content, they'll be more willing to provide data for lead generation.
To get the full white paper, they have to register.
You can let them click right through to the excerpt from the white paper, but inside the white paper is a link to a landing page where they can go and get the full white paper. In that case, they do have to pay for it ... with name and email address.