This is as common sense, as common sense can get. Make it easy to respond. Oh well, their loss. I've encountered everything from the misspelling their email or web address to having none at all. I've even seen one Einstein who published his social security number in place of a fax number.
People scan newsletter advertising the same was they flip through the pages of a newspaper.
They most often are trying to avoid reading your advertising. The key to the headline is to catch their eye before they get by you, to make them stop and read what you have to say. Well, everyone has his or her own ideas about this. This headline promises important news, and if I were over 50, I would have to stop and look. I recently wrote an ad for a friend, with a headline similar to this.