[kristopher]

I wonder how the number of daily submissions were tabulated.

If reddit were using an ID based on some sort of fixed constant (for example time) then these results could be in-fact fairly linear.

Please note that I do believe that reddit is growing!

[minimaxir]

Reddit has an endpoint where you can download all submissions. (however, due to the API limit of 100 submissions / 2 seconds, it took me about 1.5-2 months to get the 41 million submissions)

[marketforlemmas]

Have you looked at number of comments instead of number of submissions? That would seem to be a better estimator of user growth.

Honestly, I don't think that estimating number of submissions is a very good metric for the growth of Reddit (or Hackernews). If you want some proxy for its influence, you care about readership more than anything else. This thread [1] on Reddit (and the references therein) shows that 50% of Reddit activity comes from users that aren't even logged in. So even if you were just able to measure logged in users (which would still be a far greater number than submissions), you would still only estimate half the influence.

[1] http://www.reddit.com/r/TheoryOfReddit/comments/1khp85/logge...

[jedberg]

Wouldn't it be easier to just look at the public traffic information at http://www.reddit.com/about ?