If you contribute to a Kickstarter project, don't expect to see the finished product in a timely manner.

Of the top 50 most-funded Kickstarter projects, a whopping 84 percent missed their target delivery dates, according to an analysis conducted by CNNMoney.

When CNN contacted the creators of the 50 highest-funded campaigns, all of which boasted estimated deliver dates of Nov. 2012 or earlier, the site found that only eight of them hit their deadline. Sixteen hadn't even shipped yet, while the remaining 26 projects left the warehouse months late.

One in three of the highest-funded Kickstarters have not even shipped yet.

Is there anything that forces them to ship eventually? 

 Actually, Yes.

From Kickstarter's Accountability section:

"Is a creator legally obligated to fulfill the promises of their project?

Yes. Kickstarter's Terms of Use require creators to fulfill all rewards of their project or refund any backer whose reward they do not or cannot fulfill. (This is what creators see before they launch.) We crafted these terms to create a legal requirement for creators to follow through on their projects, and to give backers a recourse if they don't. We hope that backers will consider using this provision only in cases where they feel that a creator has not made a good faith effort to complete the project and fulfill."