There was a huge level of hype and press around the bundle the levels of which I've never seen. There were articles in pcgamer, Kotaku, the verge, Eurogamer, polygon etc. There were multiple reddit threads, the bundle even got it's own subreddit. It was all over Twitter as well.
Oh, well, I didn't see any of that until after the bundle ended so I don't know where I was but I still think 10 days was a short time for such a bundle. Especially since since it started to gain more traction towards the end and since they were getting way more money than they originally wanted and would have probably got a lot more if they extended it.