Many people are not really as clued up they might think on the call to action. Just getting an email out there is the main thing and then making it render the same every where takes the time. If you get your call to action right, you should get the click through in the top 3rd of the email. Benchmark email has listed some easy rules to follow to make sure you get what you want out of it:

When it comes to email marketing, your Call-To-Action (CTA) is extremely important. If you want a great response you need to ensure that your CTA has all the essential elements. It should be friendly and should reach out to people. It should successfully motivate readers to click your email and visit your website. If you feel you are not accomplishing these tasks, read on for some tips to improve your CTA…read on
Oct 22 2009, 09:36 AM

Make sure the rest of the email is still friendly though, what you want them to do is not always what they want to do, no matter how well you present it. Always give the recipients easy ways to contact you and interact with you. Maybe the call to action needs some more elaboration, have extra links further down just in case you need a little bit more trust – what if someone has been sent it form a friend?

Get the call to action right, use the tips in the article above and make sure the rest of your email supports people’s needs and let them interact with you if they need!