Conferences - I've found attending industry specific conferences and networking there has lead to the most productive leads. This gives me a chance to identify potential business and then understand who in the organization is an important audience and decision maker to get in front of to make a pitch. The downside is the cost and travel of attending conferences. Even better, if you can figure out how to be invited to a conference as a thought leader, presenter or speaker to have the admission fee and possibly travel covered.