Sure, I'll chime in to this retrospective. But first let's give credit to the one person who started this whole TAR "spoiling" at RFF, namely "Puddin". To the newbies (and veterans alike) who know nothing of this stellar detective/moderator I suggest a walk through the archived TAR seasons to see just how the "detectives" gleaned their information. Puddin was also a great cheerleader, encouraging the team with many a late night session before the next episode aired. FYI, it was Puddin who coined the title "TAR Detective" (based on a reason known to a select few veterans) which was assigned to RFF members who distinguished themselves "spoiling" the show at RFF. I wear the title proudly from the first day it was presented to me.
I believe my first season spoiling at RFF was Season 8, after being recruited from another reality board by Puddin herself. I believe Chateau, Slowhatch, and G-Man were already members when I joined, along with a handfull of talented and dedicated TAR fans. It's inconceivable that social media tools such as Twitter, Facebook, and Instagram were not available at the time, and if I'm not mistaken, the primary clue source was the 15-second preview at the end of the prior episode broadcast by CBS. Yes, it's crazy to think you could decipher a location, let alone tasks and pit stops from such a meager source. Also, the "intro flash" at the start of every episode was invaluable in determining a possible route around the world.
Personal web blogs was the only way of knowing where racers traveled, months after the fact. Those days are thankfully over with the flood of information available to today's fan. The fans are now worldwide and RFF gets write-ups in various publications including high-tech blogs such as C-NET.
But enough of this walk down memory lane and let me just say that regardless of how much spoiling we accomplish, the overriding principal, started by Puddin, that the final 3 finish order is never revealed prior to the airing of the final episode. To me the racers were not the primary motivation for spoiling, but rather the locations. Even Phil himself has said more than once, that he doesn't care who wins the race, but cares more about the "drama".