Ask HN: start locally or globally?

I am working on my own startup. The basic idea is to connect travelers in nice bars in differents cities. Own early adopters are travelers. That is clear.

I have this question: have I start with a lot of cities? Or just focus in the most touristic cities in the world (like the top 20)?

Both have their pros and cons.

## Focus on a lot of cities

Main advantage: all the users can use the site. Main disadvantage: users are widely dispersed.

## Focus on 20 cities

Main advantage: users are not widely dispersed. Main disadvantage: not all users can use the site.

What do you think about?