So a couple of days ago I was home searching the internet on my MacBook Pro for certain images to use for a project. Some of the images I found using Google Images took me to Shutterstock.com when I clicked on Visit Page. Later that day, I was home on my iPod Touch playing a game that occasionally puts up ads and lo and behold there is a Shutterstock.com ad showing the types of images I was looking at earlier. I was not logged into anything like Google, Yahoo, YouTube, etc. on either system. The only thing in common was the WiFi used. So how does my iPod know what I was doing on the MB Pro?