I’m sure you’ve heard the phrase an picture is worth a thousand words. Well in the world of online and mobile, there’s at least one instance where that old axiom is just plain wrong —email. Here’s why.

Did you know that at least half of email recipients have images turned off?

Outlook and other e-mail clients like to block images by default. This is done as a sort of privacy feature for users, as e-newsletter services like MailChimp, Constant Contact and others actually use images to track open rates (true fact).

The image is a very, very tiny one that’s placed by the sending application in your e-mail campaign. When that image is requested by the receiver’s e-mail client, Constant Contact or MailChimp “knows” that someone opened your message. It’s like a little beacon that says, “Hey, they opened your message!”

So, if your nonprofit or foundation’s event promotion, donation campaign or what-have-you basically consists of one big image, with the call to action and other text within the image file, you’ve just set up a barrier to users seeing your message.

They have to opt-in to view it, and frankly sometimes deleting something is just that much easier than right clicking to view your message.

That big image makes you look like SPAM

Whether or not an e-mail message is marked as SPAM is based on a variety of factors. One of the factors is the type of language you use in your e-mail. So, if I’m a naughty SPAMer and I’d like to tell you about the low, low cost of a certain male performance drug that I’m supposedly willing to sell you I might avoid being marked as SPAM by using an image to convey my message instead of using terms like “Cialis” in my e-mail message.

Now, obviously your legitimate email campaign has nothing to do with these subjects. However, if the text that explains what your message is about is within the image, which SPAM filters therefore can not “read”, you are more likely to be marked SPAM, because the SPAM filter has no way of distinguishing your message from the naughty ones.

How much image space is too much?

Half and half is a good rule of thumb in my book. You should at least have as much text proportionality in your message as you do have image space. I would always avoid putting your call to action within the image.