I guess it's because of the removal of the "circle of friendship" system.
One thing I'd like to suggest. I know you want to be different from other ARG's, but you shouldn't underestimate the vastness of the internet. ARGers are prone to look all over for clues - searching is part of the fun, sometimes even more fun than reaching the goal itself.
I remember from other ARGs they had a system to confirm when something was in-game. All the in-game websites, blogs, etc. had a mark of recognition.
Searching those sites can still be a giant undertaking, but it's really frustrating when you don't know whether what you've found is genuine or not.
Such a mark of recognition can be as simple as a short line in the source code of the pages, or a tiny symbol in the lower right corner. Of course this is difficult when you use real places and people who have agreed to participate with the game. But new things which you create in function of the game could be equipped in this way.
