How to check if a site user is real (without every time showing him a captcha)?

I want to count page views and/or users on my site.

How to exclude bot (or otherwise fraudulent) views from the count?

I want to make it highly secure so that it would be very difficult to write a bot that significally tampers the statistics.

My ideas of solutions:

• Use Google Analytics API (does it have such an API?)

• Show captcha before showing the page (very disturning for user experience)