It's possible, but it seems unlikely.

https://www.reddit.com/comments/z1c9z Obama's AMA. According to the sidebar, (upvotes - downvotes) = 14,700, with upvotes/(upvotes+downvotes) = 94%. Reddit recently changed their algorithms so that the 94% figure is very accurate. That means 14,700/0.94 ~= 15,600 people voted, according to the sidebar.

Here are Reddit's traffic stats for the Obama AMA: https://www.reddit.com/r/IAmA/comments/z3msa/traffic_stats_f...

The AMA brought in an extra two million uniques over two days. Also, it was one of the most legendary and historic events thus far on the internet, because it was the first time a sitting US president directly engaged with the public on a social media website.

Reddit has millions of subscribers. They can't really obfuscate the subscriber counts, because the subscriber count for each subreddit is visible every day. If it suddenly slowed down, people would notice. And the info needs to be available to moderators in order to manage their subreddit. Therefore, when /r/funny says it has 7 million subscribers, we can be reasonably certain there are at least 7 million Reddit accounts, many of which are active.

So, assuming there are only about a million active Redditors (there are probably more), and that a large number of those Redditors visit http://www.reddit.com/r/all on a regular basis, and considering that the Obama AMA was one of the most significant events in Reddit history (and indeed all internet history), and considering that over three million people viewed the AMA, it seems hard to believe that only 15,000 people voted on it.

It's possible. Statistics are one of the most counter-intuitive fields. Behaviors emerge at scale which aren't seen in the initial stages. Maybe it's possible people saw that 5,000 people had already upvoted the AMA, and so were less likely to upvote it themselves. But given the nature of politics and the significant historical status of the event, could it be true that the fate of the AMA was influenced by just a few thousand people?

Another observation: Reddit has had steady upward growth, but I remember that as of a few years ago the upvote counts were regularly reaching 3k. That number hasn't gone up too much in the meantime: https://www.reddit.com/r/all/

... but Reddit's traffic seems to have doubled since the start of 2013: http://www.google.com/trends/explore#q=reddit

If the number of voters could be calculated as a simple percentage of total active Reddit accounts, and Reddit's traffic has doubled, then why haven't the vote counts in /r/all also doubled?

That said, I'm not entirely convinced of my position. Reality is weird, and I'm often wrong. All I'm saying is that if it's true that only 15,000 people voted on Obama's AMA, and that a submission on /r/all regularly receives only ~5k votes out of a million active redditors who see it, then I'm surprised.

EDIT: The more I think about it, the more I think I'm mistaken. If it were true that Reddit compresses the vote counters for submissions, then they'd also have to do it for comments, because otherwise the top comment would regularly display a count that's way higher than the submission. They'd also have to compress the added comment karma, etc. This is where it moves from "plausible" to "the simplest explanation is that very few people vote."

Huh. Interesting.