Feel like you’re just going through the motions with your customers lately? Maybe your relationships have hit a plateau? Try changing your email subject lines. Here are some ideas to help spice things up a bit.

Subject lines can go a long way to peak interest among your customers, particularly those who read their emails on mobile devices. These few words are often the only thing they see. It’s how they decide whether to open your email or hit delete (or worse yet, flag it as junk mail and jeopardize all future emails from you).

Good email subject lines are part science, part art. The key is to find the combination that works best with your audience. Here are four factors to consider when writing your next email subject line:

• Size Matters – Think about how few words you can see in a subject line on your smartphone. So keep your subject line short. Some experts suggest limiting subject lines to 25-45 characters.
• Get Personal – Personalize your subject lines with information the receiver can identify with, like the city where they live.  For current customers, consider using their name as part of the subject. It reinforces that you have an existing relationship with them. Be careful about the creep factor – using information that isn’t public knowledge.
• Try a New Do – Consider the way your subject looks. Using capitalization or numbers can set you apart from the clutter. But be careful not to overdo, though. Some email servers consider special characters as possible indicators of spam and will filter out your email if they detect too many.
• Ask for a Date – Provide a sense of urgency by using a date in your subject.  Phrases like “3-day sale” or “Labor Day Offer” give the reader a sense that they have a limited time to act. That gives receivers a reason to open your email now rather than saving it to view later.

So before you hit send, put some thought into your subject line. It could make the difference in whether your customers come back for more or look for more meaningful relationships with your competitors.