Why do inflight wifi networks display a captcha? [closed]

When you log on to Gogo Inflight Wifi or similar, Gogo displays a captcha:

_{(source: triphackr.com)}

A CAPTCHA is usually associated with preventing automated traffic from accessing your network; however, to connect to Gogo you need to be on the plane, thirty thousand feet in the air. It doesn't seem like this is exploitable by bots (or what the advantage would be from doing so).

What am I missing?