More than seven billion mobile phones are estimated to be in service globally, with more than a billion older phones likely to be retired. A major barrier to a sustainable circular economy for mobile phones is people's hoarding of their retired phones. Old mobile phones may be refurbished for re-use or ultimately dismantled for possible extraction of elements, including 'conflict' metals such as coltan (containing elements tantalum and niobium), mined in eastern Democratic Republic of Congo and threatening wild populations of eastern Grauer's gorillas (Gorilla beringei graueri). Zoos Victoria cares for western gorillas (Gorilla gorilla gorilla) who served as ambassadors for their Grauer's gorilla counterparts in this community-based social marketing initiative. Through tracking of barcodes on satchels of recycled mobile phones, efficiency of ten different points of influence could be calculated for the 'They're Calling on You' mobile phone recycling community campaign at Zoos Victoria in Australia. Over a six-year period (2009-2014), a total of 115,369 mobile phones were donated. The Courier Collect initiative resulted in 50,883 mobile phone donations (44% of total), followed by the Static Display at Melbourne Zoo, resulting in 29,778 mobile phone donations (26% of total). The number of phones collected for Keeper Talks (at Melbourne Zoo and Werribee Open Range Zoo) was 12,684 (11% of total), and in terms of fostering close connections between visitors and the conservation campaign, keeper talks were effective as one phone was donated for every four people attending a keeper talk at Werribee Open Range Zoo and one phone was donated for every 28 people who attended a keeper talk at Melbourne Zoo. We provide suggestions for future campaigns, so that accurate data capture can allow cost-benefit analyses to be conducted. Our results demonstrate that a conservation-based organisation, in partnership with corporate sponsors and community groups can effectively influenced people's mobile phone recycling behavior, paving the way for international collaborations to maximize scale and impact.