Back in October, Facebook gave an earnings call in which it mentioned, “We did see a decrease in daily users specifically among younger teens.” This quote saw its share price slump – despite its earnings having risen 60% year-on-year. Now social media marketing company Nanigans has thrown salt in those not-quite-healed wounds by claiming that teens are the least financially worthwhile demographic on the social network. Its research found that teens have the lowest CPC (cost per-click) at £0.33 but they also generate the lowest RPC (revenue per-click) at $0.69. This stands in stark contrast to those aged 45-54 who have a CPC of $0.57 and a RPC of $1.77. In related news, Facebook estimates that 5.5-11.2% of its 1.23bn monthly active users are fake – that’s up to 137m accounts we are talking about here.