Every page on your website should have a clear call to action. In other words, it should always be obvious what you expect a visitor to do.
The call to action should be the beginning and ending of your web page. Start with the end in mind and work your content backwards. This the best method of ensuring that you accomplish your goals and meet the needs of your clients. Your call to action is the most critical part of any ad or web page, it provides the information, button or other details for your client to perform the intended behavior.
The importance of a call to action was recently illustrated in an episode of Celebrity Apprentice where teams had to design ad campaigns. One team failed to include a website or phone number or any information to lead a consumer to the next steps. You can imagine the negative feedback the team got from The Donald for this critical failure.