This option allows a first time visitor from Google to access ONE member only content page before requiring them to sign up or log in.

This is configurable on or off. You can access it on the left side of your control panel in the "Google / SEO" category as shown here:

In the Google 1st Click free control panel, you can find out more information about it from Google (1) as well as put in a custom message for a drop down box (2). This drop down box allows you to communicate with a first time visitor. You can direct them to sign up or join your newsletter etc. If you leave this box empty, then no pop up box will appear.

Informational box from Google related to the First Click Free feature:

Google tracks the visitors by IP address so that they can not abuse this "1st click free" option.