Why, you ask? Well, the subject line gets 'em to open your message. And the first sentence engages them in the copy.
Next, you can also turn your first sentence into a cool little hyper-link which is clickable.
And that is the goal of the ENTIRE email: Get them to click where you want them to go.
And that's why you'll want to harness the world's most POWERFUL EMOTION for selling, which ain't your offer, your fancy branding, but simply the use of curiosity in your messaging.
After all, it's what makes magazines, books, movies, and newspapers SELL. And this is done when people are busy...browsing Facebook, standing in line, and not even planning to buy...
And if you want to use these emotions like the weapons they are...you need my Master Class on how to craft insanely effective headlines and email subject lines.