The best sales reps are turning to LinkedIn to source for leads and maintain customer relationships. But not all reps use the online networking platform the same way, the Harvard Business Review reports. Contributor Steve M. Martin asked 54 reps across a range of industries how they used the platform. He found that while the reps varied significantly in their approach, each could be classified among four user types-"Enthusiasts," "Casual," "Personal," and "Non-Participants." For all their differences, the groups have one thing in common: They're not likely to make their initial customer contact on LinkedIn.