The average worker sends 40 business emails every day, according to a study by the Radicati Group. That's more than 10,000 emails per employee each year, or more than one million emails a year for a company of 100 people. 

Before you hit send on your next email, pause a moment to look at the very last part of your message: Your email signature. Are you and your employees just leaving your names and other basic contact details at the bottom of your emails? 

Or do you view this often overlooked part of your email messages as a valuable slice of digital real estate where you can share important messages, or promote your products and services? Have you thought about how you can use this space to share important news and information with your employees?

Here are 6 simple tips for turning your email signature into a powerful marketing tool:

1. Include a call to action (and update it frequently)

Want to turn readers of your emails into potential customers? Include a call to action, experts agree. Lindsay Kolowitch on the Hubspot blog says "the best email signature CTAs are simple, up-to-date, non-pushy, and in line with your email style, making them appear more like post-script, and less like a sales pitch."

Want to know whether anyone is clicking on your call to action links, and which ones? Track them with services like bitly.

2. Use graphics (but sparingly).

Experts agree: Graphics can bring dull, text-only email signatures to life. But don't overdo it, warns Dan Hanrahan, founder of Sigstr, an email marketing firm. He advises limiting the height of your email signatures to 100 pixels.

And even if you do use graphics in your email signatures, include essential information in text to ensure that your email signatures are readable when they are opened in applications like Outlook, which strip out graphics by default.

3. Include social icons (but not too many).

One of the best ways for potential customers to get to know you and your company better is to point them toward your social media channels. Use icons instead of text, says Kolowich, so skimmers can spot them easily. But don't overdo it, say the experts: Select the two or three most important platforms you'd like people to follow you on.

4. Minimize colors and fonts.

On Canva's Design School blog, Mary Stribley suggests minimizing your color palette in your email signatures. Pick a color from your brand, she advises.  She also suggests the same for fonts: stick to one or two fonts to keep your signatures clean and professional.

5. Use design hierarchy to attract attention to what matters.

Kolowich suggests using design hierarchy to attract attention to the most important elements of your email signature. This could be your name, which you can feature in a larger font than the rest of your signature. Or perhaps it's your company logo. Whatever you choose to focus on, be sure you vary the font sizes and weights to direct your reader's attention to what matters most.

6. Stick to the bare essentials.

Don't overload your email signatures with information. Name, basic contact details, social icons, and a call to action are enough.