How popular is Shinto?

In Japan, most people will visit Shinto shrines around New Years but not much other than that. Most Japanese people aren't very religious. Only a very small portion of the population would be considered devout. Usually, older people tend to be more devout than younger people.

Outside of Japan, it's extremely rare to find anyone practicing Shinto. There are only a couple Shinto shrines in the US, for example.