Sometimes you can use a guarantee effectively in your headline. Doing so often creates increased trust in the reader. After all, if you guarantee it, you must believe in whatever it is you are guaranteeing.

Remember Domino Pizza's unique selling proposition (USP), which was also used as a headline? 'Fresh Hot Pizza, Delivered To Your Door In 30 Minutes Or Less - Guaranteed!'

That headline worked great for Domino's, could a similar headline work for you? Think about your product or service. Do you have a USP that would make a great headline? Can you guarantee it? If so, test putting a guarantee in your headline and see what kind of response you get.

You don't have to use the specific word 'guarantee' in your headline, other similar words or phrases will work just as well, for example Brian Keith Voiles, a famous copywriter, gives as an example of a guarantee type headline, the following:

'Try Moose Skin Care System For 30 Days, If Your Skin Isn't Softer And Glowing, Return It For A Complete Refund!'

Don't forget, keep testing your headlines. Don't fall in love with any particular headline. If your headline does not produce results, trash it and use another. Use your best headline as your control and try other headlines to see if you can beat its' results.