First of all, BuzzFeed has awesome subject lines and preview text. They are always short and punchy -- which fits in perfectly with the rest of BuzzFeed's content. I especially love how the preview text will accompany the subject line. For example, if the subject line is a question, the preview text is the answer. Or if the subject line is a command (like the one below), the preview text seems like the next logical thought right after it:

When it comes to deciding how to craft that perfect subject line, there appears to be really only one area to avoid: the subject line of 60 to 70 characters. Marketers refer to this as the “dead zone” of subject length. According to research by Adestra, which tracked over 900 million emails for its report, there is no increase in either open rate or clickthroughs at this 60-to-70 character length of subject line.