Prusak.com

I received an email last night to my gmail account (my browser is chrome).
Here is what it looked like:

I wanted to learn more, so I tried clicking on a few things, but nothing was clickable.

I then turned on images to see what I was missing and got this version:

See the difference?

The ONLY call to action in the email is the learn more button at the bottom which is an image!

While it might make sense having the call to action being an image if the entire email is an image (which is not always a good idea) having most of the email text and ONLY the call to action be an image is very confusing.

Also, you should always preview your email blasts with images off before sending.