You could say that Don Corleone, played by actor Marlon Brando in “The Godfather,” was the ultimate email marketer. After all, his famous line is: “I’m gonna make him an offer he can’t refuse.”

Don’t we hope all our emails will achieve the same result?

So what kinds of offers will prompt your subscribers to open an email, click through, and actually make a purchase?

1) Use the real magic word

It’s no surprise that the most powerful word in advertising is “free.” What is surprising is the fact that many email marketers resist using it in subject lines, afraid their email will be marked as spam.

Fear not, my fellow marketers. As long as your email lists are clean (scrubbed of undeliverables, invalids, inactives and the like), you’re good to go. If it’s free, say so – loud and clear.

The email below, from Land of Nod, not only includes “free” but a few other concepts key to a good offer (more on those later):

2) Create a sense of urgency

In the example above, a sense of urgency is created by inserting “for a limited time only” into the copy. Below, Kohl’s gets right to the point in the subject line: 5 Hours Only … And the subhead drills it home with “Hurry!”

Ready for a little R&R? Repetition and reinforcement, that is. Hayneedle starts off with “LAST CHANCE:” in the subject line, followed by “ENDS TONIGHT!” at the top left corner, and “Order by 11:59 p.m. Feb. 11.”

3) A (good) picture is worth a thousand words

Much to the chagrin of all the copywriters out there, all the great copy in the world can’t make up for a lousy product image. Case in point, this email from Serious Skincare. I must admit I find it rather ironic that the email touts a “BIG SALE” and is targeted to an over-40 audience, yet features tiny, hard-to-read copy and a minuscule product image:

On the other hand, this email from Chico’s may not offer a discount, but it offers a preview of spring fashion – and a compelling image that ties it all together.

4) Offer (real) value

If your budget doesn’t allow for free anything, the next best thing is a discount. Offer a percentage off, dollars off, a special subscriber rate, etc. How you word it is just as important as the offer itself. “Buy one, get one free” has proven to be more effective than “50% off.” (Tip: Be sure your back-end systems can handle whatever you’re promoting.) Test what works best with your customers, then run with it.

5) Claim exclusivity

As in the Land of Nod email above, “exclusive” is another draw. You can have an exclusive product, an exclusive offer (to email subscribers or online only), or an offer exclusive to a segment of your list (top customers). This is what email was made for!

6) Throw in a guarantee

To this day, there still are some people leery to shop online because they’re afraid they won’t be able to return their purchases or they simply don’t want the hassle of returning an item. Remove that purchase barrier by guaranteeing your products. At the very least, make it easy for customers to return items. Include a prepaid packing label and instructions on how to return the item.

7) Lighten up on the legalese

I’ve actually seen a disclaimer that was longer than the email itself. It reminds me of those TV and radio ads where the announcer talks a mile a minute in order to get all the legal mumbo-jumbo into the spot.

Bottom line, the more legal language you have, the less likely your prospect will act on the offer. I call it the “fear factor.” Ask your legal team to move that monster to the website at least the bulk of it.

The Register actually bestowed awards such as the longest email disclaimer and most incomprehensible disclaimer. After reading them, I would have thought they’d have been in the “best spoof disclaimer” category.

The key takeaway to crafting a good email offer?

Not all people shop exactly the same way. An email offer that might be appealing to one person might turn off someone else. That’s why it’s important to feature a few of the elements I’ve suggested in your offer, in the hope that it will attract the greatest number of responses.

About the Author: Scott Hardigree is Founder of Indiemark. Connect with him everywhere, here.