I don't know about the states but Instagram is a major promotional tool for cafes and restaurants in Japan. People take photos of their drinks and dishes and share them on Instagram, tagging the cafe and a lot related tags. Meta-accounts with lots of followers then repost those and create buzz for the cafes. Then on the weekends the cafes get swarmed by people who found out about them through Instagram, repeating the cycle.

If you're in a major metro area in Japan and want to find the on-trend coffee joints, check out Instagram.