dsandler.org/wp

I had previously scraped my RSS numbers together
by extrapolating from Bloglines
subscriber data, but today’s Boing Boing article on RSS
bandwidth includes a helpful link to Boing Boing’s own Web stats page.

File type	Hits	Percent	Bandwidth	Percent
xml1	2230472	11.1 %	46.36 GB	22 %
html	1924753	9.6 %	43.47 GB	20.6 %
rdf2	225715	1.1 %	4.11 GB	1.9 %

¹ from /rss.xml and /atom.xml

² from /index.rdf

That’s right—they’ve served 50 GB of RSS/Atom data so far
this month (somewhere in the vicinity of 3 GB/day, since we’re but
halfway through November).
Straight HTML only accounts for 44 GB over the same period, which is
surprising: RSS readers are pulling down more bits of text and markup
than web browsers.

I had previously conjectured (based on a
rather larger RSS feed size, 40 KB; the logs say the average is more like
20 KB) that Boing Boing serves 22 GB/day (40 K × 11,500 Bloglines
subscribers × 48 requests per day), so my estimate was perhaps a
little high.

In the most conservative case, this means that Boing Boing has (3.6 GB·day^-1) /
(48 users·polls·day^-1) / (20 KB·poll^-1) = 3,750 unique RSS readers. Many clients don’t poll every half-hour or all day long, so there are
probably quite a few more.
What this tells me is that bandwidth problems are real, and we can
expect them to get worse as more users discover RSS (to wit: yet more mainstream press, this time in Sunday’s TIME
Magazine Europe).

Judging by these stats (and Glenn
Fleishman’s figures),
it’s clearly still
important that we repair the distribution architecture of RSS.
Even with the best-behaved clients, the growing user
population spells DOOM for polled RSS.

[Aside: Glenn’s graph shows a beautiful weekly heartbeat in RSS
bandwidth; he attributes this to well-behaved readers cooling off
over the weekend when his XML feed is completely static. I think
that’s part of it, but I’d also be willing to bet that some of this
can be attributed to clients being switched off over the
weekend. Rodrigo Rodrigues had some great p2p
membership graphs in his IRIS
workshop talk that showed many hosts disconnecting for about two
days—Saturday and Sunday.]

[Note: This article was updated
as of about 21:15 to reflect a closer
reading of BB’s stats page.]