A recent study profiled on Marketing Charts shows that promotional e-mails that include links to social networking sites produce an average of 30-percent higher click-through rates (CTR) than promotional e-mails without links. And don’t think one is enough — research also shows that the more social network links you have, the higher CTR you receive.
Most popular links:
Twitter,
Facebook
Least popular:
Digg
So when it doubt, be social… very social.
