Kickstarter is a popular crowdfunding site focused to bring creative projects to life. It became relevant for the Order of the Stick comics when Rich Burlew ran out of book copies for War and XPs and second reprinting would've cost too much for him. The project was inaugurated at January 22nd, 2012.
The pledge was wildly successful, 14952 people raising $1,254,120 in American Dollars, which was 2127% funded more than the original goal of $57,750, being the most funded creative work from Kickstarter and the most funded project by a single person for that time.
A wide variety of rewards were offered and have been gradually given as rewards for participation in the Kickstarter.
The $5000 contribution reward was described as Your original D&D character, based on your descriptions (within reason), gets a walk-on cameo in The Order of the Stick webcomic sometime this year. Plus, you get an original signed crayon drawing of that character, an autographed copy of War and XPs, and the Roy Greenhilt magnet.
The original character turned out to be Veldrina and was upgrade from the original cameo to an integral part of the story of Book 6.