A stretch goal is an extension of your target, where you specify the extra funds required to get your art to the next level.

A successful crowdfunding campaign runs on the three P's

Crowdfunding is the art of rallying your community to fund your project. 

Your campaign pitch (or your campaign description) is arguably one of the most vital parts of your Boosted campaign.
It’s your proposal, it’s your message and it’s your chance to drive home the essence and importance of your work.