I've posted before about them, and here is more evidence of the power of the White Paper. Take a look at this research from Marketing Sherpa:
Research shows that 69% prospects who download and like your white paper PDF will actively pass it on to their colleagues. In fact 36% of total downloads will be passed on to a direct supervisor.
In other words, if your white paper is good enough, it can go viral.
So, the effort to produce one or two quality white papers surely offers a more probable payout than other sales activities.
For more on white papers, see an earlier post here.