Incase some of you have not seen this, I thought I would share. My email/ads open/click rates have been improving since starting to use this tool. It's free, but you do signup for a newsletter. It's SubjectLine.com It will evaluate and optimize your subject line. you input a proposed subject line and then gives back a score (out of 100) based on known best-practices (length, word choice, urgency, spam triggers, etc.