1. Instagram, for example, has 800 million users, which is more than a tenth of the world's population.

2. This phenomenon is changing our visual landscapes on the streets and in restaurants, stores, museums and more.

3. She says the value businesses are placing on a social media look ramped up "very aggressively" over the past year or so.

4. Then, of course, there's the belief that viewing the world through your phone's camera is an impoverished way to live. ]]>