The Short Answers To Every Matt Cutts Video
"Does Google use EXIF data from pictures as a ranking factor? Potentially, yes."<p>This is a simple, but brilliant optimization.<p>With the Manufacturer & Model info from the tag you could make an educated guess about professional vs. non-professional photography and draw conclusions about website's intent.<p>With the date & time you've got relevancy of time beyond just search results. EG if you're optimizing for freshest / relevant content a "new" article that contains a recent picture with positive PR signals could outrank another "new" article that is using old pictures.<p>With geo-data you've got an obviously powerful signal.<p>And on and on.<p>It is kind of crazy to think about the sheer # of breadcrumbs we leave online for GOOG (and, ahem, other organizations) to learn about us with.<p>PS -= This is hugely useful resource, thank you for submitting!