Keep it short. Ultra-short. And when you go longer, at least make sure that the first 30 characters are enticing and informative enough on their own to get mobile readers to open.
If it genuinely makes an subject line more compelling, include a name variable. But don’t put a first name in there just because you can. Five years ago, it might have been novel to see your name in a subject line, but at this point it’s old hat.
Take some data-driven motherly advice: don’t yell and always mind your manners. Use “please” and “thank you,” and say “sorry” when you mean it.
Luring your reader with what they’ll get in return for opening, like the answer to a question, entices them to open.
As long as it’s appropriate, you’re fine using words like “now” and “today,” but don’t just shoehorn them in because you think it’ll result in a boost in your opens.
The important thing to remember here is that when it comes to sales emails, open rate isn’t the most important metric – revenue generated is. But surprisingly, promotional emails with words like “sale” and “offer” maintain a respectable open rate, and “free” sees a noticeable increase.
Don’t send fewer emails; create more specific email campaigns that are targeted and are crafted for a smaller subset of your users.