Curious if anyone can explain how this works. I understand for the most part how targeted ads work but this one has me stumped: I'm on my mac and using chrome to search and surf for various items and various sites. I'm not logged into facebook. However, when I look at facebook on my iphone it is very obvious by the ads I see that facebook knows exactly what I was browsing for on my mac. Almost instantly! Where is this information being exchanged?