We all know that we need an effective call to action on our emails and webpages if we actually want people to do something. Sign me up. Add to basket. Checkout now. Whatever it is, if you don't make it obvious what you're asking your recipient or visitor to do, they typically won't do it.
There's lots to say about effective CTAs. They should use active language that relates clearly to the action. They usually perform better when they include the offer or incentive, if there is one. They should be limited in number; give the reader too much choice and they won't know what to do. Highlight the CTA that is the most desired action and make any other options visibly less important. CTAs should generally be as high up the page as possible, especially within emails. Many recipients will be viewing in a preview pane or on a small screen device. You'll almost always get a higher click-through than one lower down.
Here comes the bit that's made me miserable. This is the main image from an email I received the other day from premium meatmonger Donald Russell. You'll see (only after playing "Where's Wally/Waldo?" for a little while) that they have a CTA. They've cleverly used a button that is almost exactly the same colour as the casserole in the image and stuck it on top. I now have Stan Ridgway's 1986 classic stuck in my head.
And not only have they made it almost impossible to pick out, it's way too low to be seen in almost all preview panes and is the least imaginative of all CTAs. They have a strong offer, so why not incorporate it into the button: Get 20% Off + Free Delivery Now