You should do that - though I doubt it'd be an exponential decay. You're going to get a series of bumps every time a post about it pops up on HN (or similar sit

You should do that - though I doubt it'd be an exponential decay. You're going to get a series of bumps every time a post about it pops up on HN (or similar site), and those bumps will probably be positively correlated with one another (note how top posts on HN are oftentimes top posts on related subreddits on Reddit, for example). Would be interesting to see, though - let me know if you do it.