The firehose is all public data going into the network right?
Isn't that pretty tiny for a worldwide social network?
And the fact one country can cause a 10x surge in traffic also suggests its worldwide footprint must be tiny...
Lots of these numbers are public and the impact of the surge can be seen here: https://bskycharts.edavis.dev/static/dynazoom.html?plugin_na...
Note the graphs in that link only show users that take a publicly visible action (i.e. post, like, follow, etc.) and won't show lurkers at all.
Every year or so, you plop in one more 10TB SSD.
I aggregated some stats when we hit 10M users here - https://bsky.app/profile/did:plc:q6gjnaw2blty4crticxkmujt/po...
It's the "main subset" of the public data, being "events on the network": for the Bluesky app that's posts, reposts, replies, likes, etc. Most of those records are just metadata (e.g. a repost record references the post being reposted, rather than embedding it). Post / reply records include the post text (limited to 300 graphemes).
In particular, the firehose traffic does _not_ include images or videos; it only includes references to "blob"s. Clients separately fetch those blobs from the PDSs (or from a CDN caching the data).