Not just e-commerce sites—change.org shows "### have signed," where the number is programmed to tick upwards at a somewhat randomized rate. This is simply dishonest—a lie designed to make you feel like you'll be missing out unless you sign.
I've pondered this for a while, if this disingenuous design pattern is biasing people to sign their names, in addition to their shady user engagement email spam with click bait polarizing email subject lines and targeted spam "Sizzle, the discussion keeps evolving..."
How they promote petitions after you sign one by showing you 'trending' high shock value petitions is pretty scummy way to grab your attention and stay on the site signing more petitions. There has to be a better way to drive engagement than shoving polarizing clickbait petitions in my face.
Don't believe me? Sign up for the site and sign a petition, enjoy the flood of petition spam in your inbox.
It's also pretty common in event promotion. Sell tickets in tiers, but make the capacity of the first two tiers ridiculously small, like 10 or 15 in total. They'll sell out relatively quickly, and it feels like the ticket price is going to jump, so if you do it right, most people will buy their tickets at a slightly inflated rate, and you make more money.
Then you promote online saying stuff like "ABOUT TO SELL OUT! ONLY 50 TICKETS LEFT!" the week before to drive more sales. :P
Couldn't that just be attributed to a log that is compacted to a count? I would imagine a system like change.org needs to handle plenty of people all of a sudden signing that a append-only log would be sufficient for.
As for the randomness I'd leave that up to the randomness of people signing up.
Of course I could be entirely wrong but I can see if a technical reason why it wouldn't go up cleanly, similar to YouTube views, they're not realtime.
Example: https://www.change.org/p/target-stop-filling-the-world-with-...