Omnicom's DDB unit just released a study indicating that while Facebook's influence continues to grow in emerging markets, "in the mature markets fewer brands are being followed and fewer brand fans
are recommending brands to friends, all of which raises the value of engagement."
The study, which was a collaboration of DDB Paris and OpionWay, can be accessed here:
https://ddbworldwide-dropboxkathymanning.pbworks.com/w/file/45658024/Prez_Fb_ANG_LIGHT.PDF