A brand (or a new product offering) is nothing more than an idea. Ideas that spread are more likely to succeed than those that don't. I call ideas that spread, ideaviruses. Sneezers are the key spreading agents of an ideavirus.
These are the experts who tell all their colleagues or friends or admirers about a new product or service on which they are a perceived authority. Sneezers are the ones who launch and maintain ideaviruses. Innovators or early adopters may be the first to buy your product, but if they're not sneezers as well, they won't spread your idea. They're selfish in their use of a new idea, or they don't have the credibility to spread it to others. Either way, they're a dead end when it comes to spreading an idea.
Every market has a few sneezers. They're often the early adopters, but not always. Finding and seducing these sneezers is the essential step in creating an ideavirus.
So how do you create an idea that spreads? Don't try to make a product for everybody, because that is a product for nobody. The everybody products are all taken. The sneezers in these huge markets have too many choices and are too satisfied for it to be likely that you will capture their interest.
The way you break through to the mainstream is to target a niche instead ofa huge market. With a niche, you can segment off a chunk of the mainstream, and create an ideavirus so focused that it overwhelms that small slice of the market that really and truly will respond to what you sell. The early adopters in this market niche are more eager to hear what you have to say. The sneezers in this market niche are more likely to talk about your product. And best of all, the market is small enough that a few sneezers can get you to the critical mass you need to create an ideavirus.
Then, if you're good and you're lucky, that innovation will diffuse. After it dominates the original niche, it will migrate to the masses.
This tidbit is from the book Purple Cow by Seth Godin