This bit of text turns your message from something your subscribers will merely read into something they’ll respond to. They may reply, download, share or even buy – it all depends what you ask.
And it depends how you ask it. Write a wimpy call to action that no one notices or gets excited about, and you might as well not send an email at all. But make it eye-grabbing and attention-snatching, then position it perfectly, and you can sit back and watch the responses roll in.