by By Jonathan Vatner | November 12, 2009

EventSocial screen shot

 With eventSocial software from BDMetrics, confirmed attendees of large events can search their social networks -- Facebook and LinkedIn, for example -- to see which of their colleagues are registered and encourage the others to sign on. The Direct Marketing Association tried it for a convention in October, and within three days, 687 attendees sent out 3,265 invitations to attend. Cost: $5,000.