Official Definition of a Dominant Selling Idea

You remember in a previous post: we described the Dominant Selling Idea as positioning incarnate? The focal point of maximum, motivating, differentiating power? It's time to lay down an official definition to work with from here out.
In broad termes, we explained previously that a Dominant Selling Idea is your "motivation difference" - the one difference that tips the scale in your direction versus all others at the moment of purchase.
Then we got more specific and said, "The one thing that guarantees you a motivating difference is to be considered #1 in a desirable specialty, a specialty that contains all five Selling Ingredients." We call it a #1 specialty because it's:

Superlative... Means you're #2 at something, the best in class.
Important... Means that something really matter.
Believable... Means there's a logical reason why.
Memorable... Means there's an emotional hook that penetrates and is remembered until purchase time. It makes it the difference we not only need, we want.
Tangible... It's real; we trust it because we've experienced it and it performed as promised.

Then we added the final piece:
A specialty with all five ingredients is just another #1 specialty... until it is attached to your name. Then it's your #1 specialty. Then it's a Dominant Selling Idea.
And that, friends, is what it comes down to.

A Dominant Selling Idea is:
The fusion of your name and a #1 specialty in the customer's mind.
"The world's safest car" is a #1 specialty.
"Volvo is the world's safest car" is a Dominant Selling Idea.

The DSI isn't a tag line (although if you're good, it can be, as we'll see later). It's the thought that flashes into the customer's head when she either hears your name or thinks of the specialty she needs. It's a quick and simple mental phrasing that - regardless of wording syntax - brings together your name and your #1 specialty every time.
XYZ is (fill in the blanks):

The only one with _ . The only one with a Tootsie Roll center.
The best _ . The best TV picture.
The #1 _ . The #1 car rental company.
The most famous _ for _ . The most famous island for SCUBA.
The _ est _ . The fastest car.
The _ company. The consumer-driven health insurance company.
The _ that _ . The soup that comes with great big chunks.

The DSI is the shortest, leanest, most succinct verbalization, visualization, or actualization (moment of performance) that rings the five bells for the Five Selling Ingredients in the target's mind.
In fact, it's worth tattooing the catchy acronym we made up for Superlative, Important, Believable, Memorable, and Tangible backwards across your forehead so that every time you sneak out to the lavatory, you'll read it in the mirror: SIBMT.
With these five ingredients, your name and specialty become a fully installed, living Dominant Selling Idea in the mind of your target. Without all five, you might generate thoughts or impressions that lead to trial - but it is not the real thing and not sustainable.

In the end, it all gets back to the simplest, most profound notion in all of marketing, if not capitalism: "the difference that makes me want to buy from you."