To understand the rest of this post, let's all take a quick field trip over to io9 and read a post about their failure to kick off a grassroots ARG. You can come back when you're done.
OK, still with me? Great. Let's recap: io9, who famously dislike ARGs in the first place, got it into their heads to make a small, "generic" ARG, printed a bunch of postcards to hand out at Comic-con to promote it, and -- when the effort found no players -- called the grassroots ARG movement a sweeping failure.
This sort of failure had happened before -- heck, I made the same mistake with my Lost Bukkit micro-ARG. The failure I shared with them is one of not successfully putting the message in front of the intended recipient. It's true that the audience at Comic-Con is probably more dense in potential ARG players than many other venues; but it's an audience simultaneously being bombarded by marketing messages from hundreds of other sources. One little card in a swag bag isn't likely to make a big impression.
The tried-and-true announcement on Despoiler or mailing a mysterious package to Jonathan Waite techniques aside, there are certainly other and more focused ways to bring your message to a receptive audience. It's been done, you know?
But aside from that, let's look at their little thought experiment a little harder. Even if they'd hit the mark with the rabbit hole, I doubt the ARG would have gone very far. Why? Because they were producing an admittedly half-assed effort, and when you phone it in, the result shows in your work. They called their own project generic! And if you can't muster the will to care about your own work, why should anyone else?
So, OK, io9 made an ARG that failed. But their conclusion -- that grassroots ARGs simply can't work -- is eyebrow-raising, not least because it's patently untrue. Again: It's been done, you know?
Let's transfer this entire experiment to another medium to show how ridiculous the conclusion is. Let's say that you decide web video is pointless and stupid, and nobody can get anywhere that way. So you write a script in an hour at Denny's, then you and your buddies spend a day filming your half-assed zombie epic. Maybe you make a site, and then you upload your video to YouTube. And then... nobody watches it. You get maybe forty hits in the first month, and that's your mom and the people she emailed the link to.