As defined by Oxford, a call to action (CTA) is “a piece of content intended to induce a viewer, reader, or listener to perform a specific act, typically taking the form of an instruction or directive”. A good example of a is “Buy Now” or “Click Here”. Most of these prompts are in the form of a button or link. Call to actions are very effective when they are obvious and clear to site visitors. They should entice them to join a newsletter, fill out a form, buy an item, or follow another directive.