On Fri, Feb 10, 2006 at 07:34:35 -0500,
Doug McNaught <doug@mcnaught.org> wrote:
> Bruno Wolff III <bruno@wolff.to> writes:
>
> Or, just start your sequence counting at 1000000. Or use bigint and
> start it at a billion.
That may work if you only have access to one id number, but you don't need
too many id numbers before you can start making good statistical estimates
of the number of users.
In one of my math classes, I was told a story about how statisticians
estimnated the number of tanks produced by germany during world war II
based on serial numbers found on captured tanks. This was supposedly despite
the Germans doing things (leaving gaps and the like) to make this harder.
And supposedly after the war, the statistical results were supposed to have
been more accurate than estimates obtain via other means (such as spies).