I've heard/read Ken McCarthy and John Carlton both say they've bought products because of one bullet. No doubt many others have done the same.
That's why it's always good to err on the side of more bullets, not less. You never know which one might grab the reader and compel him or her to buy.
And sometimes, it is just ONE that seals the deal.
Also, to add to the bullet writing advice, it's good to break them up into series of 7. Clayton Makepeace wrote an article on this, and he really likes seven as a "magic" number, if you will.
Write seven bullets, then a paragraph or two in between, then another seven, another paragraph and so on...
Then there's A/B bullets (or whatever name you want to give them) where you write a bullet, then expand on it in a second sentence (often putting the second half in parenthesis).
Two examples:
(taken from Gary's site,
Bencivenga Bullets )
How to harness today's most powerful secrets of viral marketing (where your prospects and customers become your enthusiastic sales force).
How you can increase your chances of success when launching a new product by 300%-500% with another simple strategy. Yet very few marketers, even veterans, have ever heard of this.
Another example, not from Gary:
Need money? God’s blueprint for creating wealth and achieving any goal. (John D. Rockefeller ran with this secret and created a vast oil empire). (page 16)
Plus, you can do a compare/contrast which deepens the benefit of the bullet. Rather than expand on the original benefit, make the second half of the bullet what happens if you don't do so...
Again, from Gary's site:
The single most important secret for marketing anything online. Violating this rule is the most common cause of failure.
Another example (not from Gary)
The key to keeping every decision you make (breaking this is an important reason why many of your decisions become “impotent” and are never fulfilled…) (page 11)
Yet another technique is to
bold every other bullet, which I've seen many marketers do. Haven't come across any A/B test results on how effective this is, but probably worth testing.
Maybe Subtle has research or comments on whether it causes undue eye-strain or adds effectiveness when bolding every other bullet.
In any case, as Ken McCarthy says, bullet writing is arguably the most important thing you need to learn in becoming an excellent copywriter. If you can write great bullets, you certainly can write great headlines (which may come from one of your bullets, if you end up writing those first)
Hope this helps.