Any time there is an action you want a reader to take, a Call to Action should
instruct the visitor what to do. This means using active verbs when you write,
and crafting hyperlinks to be clear instructions that resonate with your visitor
at each step in the conversion process.
A good Call to Action resonates with the action the visitor needs to take, as
opposed to the technical function that is performed. For example, if a user has
entered an email address to sign up to your email newsletter, the action button
should say “sign up” and not “submit”.
Consider as well what actions mean offline. Again with email newsletters, “sign
up” can have very different connotations to “subscribe”. Further, “subscribe” is
very different to “subscribe for free”. Whereas subscriptions have connotations
of costs, “sign up” does not carry the same burden. However, “subscribe for
free” could imply greater value – something that would normally carry a cost
is available to you for free.