Kickstarter is NOT:
An investment platform.
A pre-order platform.
A charity platform.
Kickstarter is a Crowd-Funding platform and a gamble, to call it anything else is inaccurate.
Kickstarter exists to help artists and creators, of absolutely any medium, gain the funding in order to produce something that they can not afford to do otherwise. In some cases it's an artist seeking to make a sculptural piece that they cannot afford all the material for on their own, in others it's an author seeking to get enough money to get their novel(s) professionally edited and printed (along with possible marketing expenses).. it can also be a game developer, be it single or entire company, looking to get a game put together that is outside of what a normal publisher would pick up. It can be a group producing their own tabletop RPG.. it could be a film maker trying to get his Steampunk web series off the ground. These (and more) are all just examples of projects I personally have backed, the list of potential KS projects is endless.
Kickstarter only really requires a few things:
Your KS campaign has to be for a project- it can't be a "fund my vacation" (Now it could be "I want to produce a book of underwater photographs, fund my 5 month SCUBA diving adventure to get the photographs for the book." - whether or not that would be a success is an entirely different story), it can't be a "I'm starting a business!" (Creating a business can be part of what you're doing, of course), etc. There has to be something at least semi-artistic, that has an end result.
You must set an amount of money to seek. (No "just give me money, whatever I get is good")
You must make good on any promises you make for reward tiers.
There is no requirement of goods with any form of monetary value being sent to your backers.
Let's go back to the "underwater photography book" project, just for shits and giggles. You could have the only reward be "A personalized thank you email".
Kickstarter is meant to appeal to the people who want to help awesome independent artists create something- That it's been considered some kind of "pre-order" system and a marketing tool (Fuck you, Trick Concepts) is horrible. It's grown way to gorram big.
That aside:
As has been mentioned, Kickstarter only ever takes the money if funding is a success. That isn't to say that you'll never lose your money though, unfortunately.
Projects fail, it's not common (yet), but they do sometimes.. someone miscalculates costs, runs in to a major snag, personal issues, death, etc.. Life happens to everyone. Sometimes, also, people are just shit business men and/or con artists.. Kickstarter has a lot of potential to con artists, honestly.
That said, however, Kickstarter does offer some legal 'protection' to backers. Creating a project you are required to read and agree to the ToS/contract, which indicates that you have to "deliver the promised rewards for tiers by the date promised" or refund the money of any backer who has requested otherwise.
May not seem like much, but the way it is written gives backers the ability to pursue legal action against the project creator if they fail to deliver.. of course, Kickstarter has all their information on file. >.>
Is one backer going to pursue legal action? Probably not, since most pledge for $50 or less. However, if it becomes apparent that someone was using Kickstarter as a scam platform, a large number of the backers can band together and form a lawsuit- which has happened at least once.
In general, some simple rules to backing Kickstarters that will help you not get burned:
1) Never back more than you can afford to lose. Seriously.
2) Pay attention to things like what kind of experience the creators have in the field they're working in.
3) Watch for "too good to be true" projects.
4) Back projects that are already in the works- it shows that the creators are passionate about what they do and just can't afford to do it on their own dime anymore.
5) Only back projects that the money they're asking seems reasonable for the project they're working on.
6) Never be afraid to cancel your pledge if something just doesn't seem right.
(For the record, I've been using Kickstarter since almost the beginning, have backed 24 projects (plus 2 I've backed out of), 3 of those have failed. Of the remaining 21, 12 have been completed, and the remaining 9 are all still actively plugging away at their work- The oldest 'most recent' update is from 1/12/13.
I am stopping with Kickstarter for a while, simply because I've spent too much money on projects >.>)