Locals and tourists on Flickr has set of interesting map ( 99 cities covered ) which is similar to heat map displaying pictures taken by locals vs pictures taken by tourists from different city and the outcome can be used for huge profits as they tell you where tourists roam around more. Blue pictures are by locals. Red pictures are by tourists. Yellow pictures might be by either Here is one for San Francisco
That’s definitely an interesting take. I never even considered the idea of monetizing a photo website based on gps tags for instance.
Good food for thought!