1. You're asking too much money
2. The reason of your crowdfunding is too vague
3. The introduction is not convincing
4. The rewards you offer in return are not good enough
5. Your crowdfunding page hasn't gone viral...yet.
6. You're not working hard enough for it
7. You don't have enough friends
8. Your goal or project is not crazy enough
9. Your nerd level is a bit low
10. You're using a bad profile picture
11. Your focus is too much on the money
12. You don't have a cat
Use the above knowledge wisely, and good luck with your crowdfunding. I would love to paste a link here to my crowdfunding page, so I can go viral too, but that would be spamming. Remember : Spamming will irritate people, and people who are irritated wil not donate for your project !