The radio ad is sort of the red-headed stepchild of advertising. It's all around us, yet it's not nearly as lauded or talked-about as extravagant Super Bowl ads or expensive print inserts. However, if you do have a copywriting job or find yourself writing ads for freelance, it's something good to know how to do.

Writing a radio ad isn't that difficult, especially if you have funny ideas and a client that is open-minded. Otherwise, it's just a matter of getting information across and following a format.

If you're writing your first ad, flip around the stations and listen to the different varieties you'll hear. Some are straightforward 30 second spots. Others are "donuts," where a standard beginning and end is used but the middle is utilized to drop in changing information.

If you've written in script format, you'll be pretty comfortable writing in radio format. Check out a few samples. If you haven't written script, this article has some tips on how to add voices, what tone to use, and so on.

Before you turn in your script, read it out loud, slowly, in front of a clock with a second hand so that you know that it's as short as it needs to be. Also, think of the extras. What type of voices would you like reading the script? Will sound effects be needed? How about music? Especially if you are thinking about a particular song in the background but you can't get the rights, it's helpful to describe the tone of the music in mind so engineers can find something similar.

Here is an article on how writing radio ads can make you a better writer. This I guess is debatable but it is an interesting exercise in trying to get as much information across as you can in in a small amount of time. And here is a site for radio copywriters where you can see what people are talking about and using to brainstorm.