Discord is lowering the upload limit for free users from 25MB to 10MB, citing operational and financial reasons.
Discord isn’t exactly known for generous file-sharing limits, still, the messaging app offered a 25MB limit to free users. The company has now updated its support page to reflect the upload limit for free users has been lowered to 10MB.
ETA: I stick by my premise and my conclusion (storage management isn't expensive, and it's probably a Nitro thing), but my math may be wrong and my usage is apparently not normative. The costs are probably not so negligible, but I would still assume they aren't as low as they want us to think.
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Discord has 200,000,000 MAU. If every single one of them uploaded a file every month (of pretty much any size) and Discord tossed it into an AWS S3 IA bucket, it would cost them $500 to store that data. Their total S3 bill for storage would be five hundred US dollars. Storage is dirt cheap. AWS doesn't even charge per gigabyte on that storage type, it's so cheap; they charge for downloads.
So, ok. Let's talk downloads. If each of those files were 25GB and downloaded twice (probably an underestimate, but not everyone is uploading files, so I'm going to make the completely unfounded assumption that it'll all shake out), it would cost them a couple hundred thousand dollars. Which, ok, that's much more significant than $500. But Discord made $575 million last year—so the S3 download costs would be 0.03% of their total revenue. They probably spend 2-3 times more on coffee.
Storage management is emphatically not expensive.
My guess? They just saw that the higher upload limit was eating into their Nitro subscriptions.
If every one of those users uploads one 10MB file, that would be two petabytes of data. At S3's IA prices that's $25k/month. And people are uploading far, far more data than that.
I'll have to check my math again. But are people uploading more than that? On my friend server, with 50 people, we've had about a dozen uploads all year, and they're all pretty small PDFs and images. Everything else is rich links.
It’s heavily used at many universities. Think notes, images of whiteboards, full textbooks, pictures of tests, shared multiples times daily by tens of thousands of people. It adds up very fast.