Anyone can use Kickstarter. It's mostly used by creative businesses like Game Developers, Musicians, Artists, Authors, etc. who lack the funds
to get their products put into well, production. A Game Developer may use the money to hire programmers, or a band my use the money to pay
for recording equipment. It's not uncommon to have a pledge goal, and to have some kind of kickback for your backers. For instance, those who
donate $5 may get one copy of your album. Someone who donated $100 might get a copy, and have their name printed in the Special Thanks
credits in the liner notes. Someone who gave $1000 might get to spend 45 minutes with you for dinner after a live set in their area.
If not enough people donate, and you end your Kickstarter then you are supposed to refund the donations.
Now with all of that said, I have also seen Kickstarters for non profit programs, charities to regular inventions where a creator came up
with a product idea, companies told them no when asked to buy or fund the idea.
Not all Kickstarters are successful, and out of the ones that are, not all of them are smashing successes. But from what I understand
you don't have to have a full on small business to use it.