Successful projects averaged 38 days while unsuccessful ones averaged 43 days. A short campaign is often better, such as 30 days. If you are raising a lot of money, consider 60 or 90 so you have time to build momentum.
Successful projects averaged $5,487 while unsuccessful projects averaged $16,365. Asking too much is a common reason for failure. Set reasonable goals. It's a good idea to start with small projects -- raising a few hundred dollars is quite doable, and a few thousand possible. Raising $10,000 or more is really hard.