It is nearly impossible to over-state the importance of an email's subject line. In my days as a franchise marketer, I've written well into the thousands of subject lines.

Depending on what you were doing in February 2011, it’s possible that Google Panda is a four letter word around your office.

Frankly, if your franchise hasn't thought about your email send times, you're probably losing out. As you'll see below, what time of day you send email can make a pretty significant difference in the amount and type of engagement you get.