MSNBC.com:

Most successful marketing tales begin and end with a well-plumbed niche. In other words, the marketer has found the most-qualified group of prospects and motivated them to action. You’ll rarely see a company that’s risen to the top using a shotgun approach–targeting a mass audience indiscriminately–yet this is where many entrepreneurs trip up.

Failure to isolate the most-qualified niche can waste marketing funds, time and energy. I get e-mails and phone calls from entrepreneurs who tell me “everybody” can use their product or service. The trouble is, even the most well-financed business can’t afford to reach everybody at once. And even if they somehow could, their message would have to be so generic that many different types of prospects wouldn’t feel motivated to take action…