What’s in a subject line? A lot, actually. If you’ve ever spent time in the world of email marketing, you already know that a great subject line can be the difference between a campaign that drives results and one that flops. The best subject lines are usually short, pithy and promising something valuable inside the email (without misleading the reader). That kind of writing takes skill and experience, which makes it hard for small businesses that don’t have an email or content marketer to do it for them.