How “View Count” is best implemented?

Question

On any website, such as on StackOverflow, each question has a view count, and user reading a question but has previous read it won\'t count twice.

I have some ideas abou

Answer 1

When most of the visitors to your site are registered it's relatively easy to make sure none of them are counted twice.

I'm not sure if SO counts views by guests. I suppose I could check but it's late.