I signed up 10 years ago when I just made NW Silver Elite with a trip to Europe, and to Japan when I was in my 2nd year of university.

I have since flown over 600,000 miles for fun (not a single work related mile), visited over 100 countries, and 30% of my flights during that time are up front without having paid for any of those (apart from the famous CNZ mistake)

Without Flyertalk, and/or points, very little of that would have been possible.