Are you good with animals? Spread the word to friends and neighbors that you're available to watch their pets while the owners go on a vacation or weekend trip. Pet owners often feel more comfortable leaving their furry friends in the care of an individual rather than placing pets in a boarding facility, so getting referrals shouldn't be too difficult. If you can't commit to lodging animals in your home, consider starting a dog walking or waste cleanup business.
Every product cannot be defined by its market niche. The niche market is highly specialized, and aiming to survive among the competition from numerous super companies. Even established companies create products for different niches; Hewlett-Packard has all-in-one machines for printing, scanning and faxing targeted for the home office niche, while at the same time having separate machines with one of these functions for big businesses.