I'm not experimenting so much as trying to provide a beneficial service (at 6am the differences blur significantly though).
I'd say around 25% of xkcd's are remotely relevant to this site, the question is whether or not an automated source of 1:3 signal/noise ratio is worth it.
The "problem" of bots and news sites is an interesting one, though. But why not experiment on Reddit, rather than HN?