Pattern Chest, part of BundleSites, is modeled on the Bundle of Holding, a site that sells tabletop roleplaying game .PDF rulebooks. Since its founding in 2013, the Bundle of Holding has presented hundreds of bargain-priced, time-limited offers from over 250 publishers. The site's 60,000 customers have bought more than 300,000 bundles. Now BundleSites has adapted that model to other hobbies and interests.