OT: why do web BBS's and blogs get so slow?

[Paul Rubin]

Josiah Carlson <jcarlson at nospam.uci.edu> writes:
> Quoting the latest news post (http://www.livejournal.com/users/news/)
> "We now host over 2,000,000 users, roughly half of which are active in
> some way."
> 
> 'Active in some way' are those who visit and check their friends page,
> those that post updates to their own livejournal, or those that post
> replies to entries/replies on livejournals, I believe in the last month.

OK, "active in some way" can mean read-only users who neer do anything
that causes any DB updates.  It can also mean someone who posts a
comment once a month.  Also, that doesn't say how much hardware they
use.

> 30k visitors/day,

Another informative number (about 1/10th as many visitors/day as
Slashdot gets).

> many doing more than one thing when they visit (check their friends
> page, post some replies, update their own livejournal, etc.),
> everyone hitting different parts of the database, many causing
> database updates (without updates, livejournal is worthless), etc.

OK, I'm not familiar with all LJ features, but so far this doesn't sound
too bad.

> No offense, but I'd love to see you write a BBS/Blogging software that
> does that - in any language.

I have some curiosity about how to go about that (hence this thread)
but at the moment I don't have powerful enough motivation to actually
want to do the work.