You could have the best sales copy in the world but if you don't ask for
action at the end of your letter than the majority of the time you will lose
your prospect.
They may be thinking that the ad was extremely compelling, hard to tear
away from, and that the product was interesting, but a call to action is the
last step in the sales process that pushes them to buy.
Without it, many visitors simply leave, or don’t know what to do.
It is important to remember that your sales process should give the reader
the incentive to buy. Waiting for the reader to come up with the idea to
buy is simply bad advertising. Give the reader a reason to act fast before
you lose their attention.
There are a few different methods to approach a call to action, but
urgency and scarcity are going to be the most effective ways to trigger the
urge to buy.