How accurate can Visitor’s map be?

Hello,

I’m thinking of using Visitor’s map on my wordpress blog.

1. Does this plugin also work for South Korea as well?
Would this be able to tell me from which city in South Korea the visitors are from?

2. I wonder whether I can tell which post a specific visitor has viewed.
What I want to figure out is that whether people from a particular region are especially interested in certain topics from my blog.

Look forward to your answers.

Thank you very much.

Sincerely,

Jayhee