[uxp100]

I think the display strings thing is because exact number of impressions etc is slightly sensitive information. The whole site was "gamed" from the start, but providing exact vote counts makes it easier for other people to game. I guess. Don't really know, but I do believe that the numbers given by reddit, for example, are exact, but fake. Fuzzed a bit. HN also hides some of this, or behaves misleadingly, your downvotes don't always count, I think.

[formalsystems]

They would display numbers less than 1000 as-is, and only start adding the "k" and "m" prefix after the 4-digit and 7-digit threshold was crossed.

[bkilrain]

But how could they maintain an accurate count? Maybe they were just persisting the user-friendly format alongside the actual count...

[bonestamp2]

The endpoint of the API is probably just rounding the accurate number and returning a friendly number... or it's all bullshit anyway.