A few years ago, it was not uncommon to see subject lines that were full sentences. Robust and info-heavy, these subject lines told the email marketing recipient everything they  needed to know.

Not anymore. Thanks to the shrinking space due to chat programs and more, expect that your subject line will have to be one part innovation and two parts shorthand. Remember: you want to keep your subject line under 45 or 50 characters. Here's how to do that:

• Use common abbreviations when possible.
  Some common abbreviations include:
  Included – Incl.
  Attention – Attn.
  Limited – Ltd.
  Five – 5 (use numerals instead of spelling out numbers)
  Association – Assn.
  October – Oct. (abbreviate months when you can)
  
  Remember: you don't want your email subject line to be a long string of abbreviations, however, one or even two may work to keep your character count down.
  
  

• Focus on one brand. If you're sending a sales email pumping up a big sale, put the name of your most popular brand in your subject line rather than many. This will cut back on space in a major way.

• Throw out the rules on grammar. It's tough to put together a full sentence in less than 50 characters, so forget everything you ever learned in elementary school in relation to grammar. In the newsletter subject line world, sentences only get you truncated.

• Avoid text-speak. Unless your email list is strictly young and hipster, any email with the subject line “gr8 deal 4 u” is only going to get your email dumped. Period.

Your subject line is as critical as anything you put out there. A bad one will sink your open rates and destroy your ROI. Even though it's tough, work within this email campaign framework to shorten your subject lines and keep your open rates high.