TerraCycle, one of the world's foremost collectors of non-recycling  waste, has found success with its engagement  strategies, said Albe Zakes, global VP of media. Of the organization's  30,000 Facebook fans, over 75% are monthly active users, and over 60%  are weekly active users—numbers that are earned through engagement. TerraCycle's low-cost social marketing is centered on contests,  giveaways, promotions and cross-promo opportunities. And while the costs around developing a Facebook game are huge, Zakes said that TerraCycle found a small social gaming start-up that aligned with the organization's  socially responsible views and partnered with them to make a Facebook  game based on the TerraCycle recycling model. They got 100,000 users in  the first six weeks, which increased site traffic by 21% and boosted  e-commerce, making Facebook a revenue source, and not a cost.