Nothing kills a reader's momentum quicker than a section of text in all caps. Blocks of capital letters are extremely difficult to read, and tend to immediately turn readers off. On average, upper case type is read approximately 13 percent slower than lowercase text. The reason for this is simple: Readers are used to lower case type, and actually view words as pictures, allowing them to put sentences together ahead of the point they're reading. Using large blocks of capital letters cause readers to focus on individual words rather than taking in a whole sentence. Don't let your message get lost in capitalized text!

Also, you shouldn't use all capital letters in your headline. It's standard industry practice to write headlines in upper and lower case. Your headline is the first thing your readers see, and its goal is to lead them smoothly into the body of your release. Make sure it's easy on the eyes!