You’ve got targeted traffic coming to your site. You’ve made a big, passionate, and clear promise on your landing page. But you’re still not making the sales you’d like.

It could be because your offer sounds too good to be true.

Believability above a certain point makes sales; below that point it does not. Ad copy must make what lawyers call "a prima facie case" -- that is, a case that warrants a trial in court. Only the court is the consumer, and the trial is buying and using the goods.

Here are 6 tips to help increase the believability of your copy ...

Figures - Ivory Soap, as we all know is 99.44% pure. Would it seem as pure if it were advertised "almost absolutely pure"?

When a quotation is made from a book or from the media, not one in a thousand will verify it, yet it is worth your while to cite the exact volume, chapter, and page when quoting.

Figures are the height of exactness, and exactness is characteristic of truth. Vague generalities slip off the human psyche like water off a ducks back.

Proper Nouns - To say a great western city, instead of Denver is to create suspicion.

Mr. Rockefeller is conceded by all to have been one of the richest Americans, but if so described, and not named, readers unconsciously score one point against the credibility of the copy. Even further, John D. Rockefeller is better copy than Mr. Rockefeller. Proper nouns are almost as valuable as figures in advertising.

It is more believable to say "styles now reigning from Rue de la Paix, Paris, to Fifth Avenue New York" than "styles now reigning from the fashion centers of Europe, to those of America".

Reiteration - "A Suit Of Clothes FREE!" -- an incredible statement...over and over the ad stated a suit of clothes could be had without cost, fully a dozen times. You don't believe it in the headline, or in the first or second paragraph, but it is human instinct to be impressed by repeated and emphatic repetitions of any statement, however extraordinary. The arrested man who says once, sullenly, "I am innocent!" and then stops, is probably guilty, but he who repeats the phrase incessantly and earnestly shakes the strongest conviction to the contrary.

A preposterous claim becomes believable, merely by making it a number of times, even without adding any further evidence or explanation.

Local Connection - We are more inclined to believe advertising that tells us how happy the locals are with a product, and want to buy that brand for no other good reason. Nobody knows quite why, but we trust proximity. If we hear our neighbors have bought something, it means more to us than it should.

Perhaps we harbor a deep-seated trait from our ancestors. Strangers and far off people are still presumed crafty, and hostile by the savage that sleeps in our sole.

Testimonials - Some things never go out of style, and the testimonial is one of those things. They shouldn’t be edited, and should include as many details of the giver as possible. A well-worded one from an obscure person is often worth more than one from someone famous. To be most effective, a testimonial should site specific results. It’s not enough that a customer say that they are happy with your service, or that they feel they got their money’s worth.

When asking for testimonials, dig for specific “before and after” measurements. You want statements like “We saved $450 on our heating bills last year after installing XYZ windows. That’s 35%!”

Credentials Before launching into product claims, it’s critical you tell your reader why they should listen to you.

After grabbing the reader’s attention with your headline, and quickly making a big promise, this is generally the third thing you want to impress upon the reader.

Quickly, and powerfully demonstrate your credentials, experience, and track record. This can be achieved either directly in the running copy in your own voice, or in a sidebar using another voice.

Sometimes it even makes sense to add some kind of a credibility element in the pre-head (sub-headline in smaller font above the main headline) at the very beginning of the copy.