Make sure you’re not being overly ambitious, but also make sure you’re raising enough money that will cajole the target to consider your offer.
Stretch Goals are a great way to help you grow your campaign once it achieves its initial goal, so use them strategically.
Things to think about before posting your Cajole:
How many people are you reaching between your friends, followers, additional people and organizations you have involved in your Cajole? The larger the addressable group, the higher your goal could be. Also think about how involved and active the followers in a group are. If they are very active and feel strongly for your cause, you may be able to achieve a higher goal.