[CLUE-Tech] web user ratios?

[Jeffery Cann]

The company for which I work wants us to estimate how many users our shiny new 
web application will support. 

Using load robots, we have determined the amount of concurrent users which the 
servers will tolerate before the performance of any single request becomes 
too slow (e.g., 100 users). Now we need to extrapolate to a the total number 
of (paid) users that we could support. Is it 1,000? 10,000? 100,000? The 
rationale is that only a percentage of the total users submit requests at a 
given time. 

So, the questions: What ratio of total users to concurrent users is a 
reasonable estimate? Is there a standard ratio folks use for web 
applications? What is a good way to measure our ratio, since it's possible 
that this ratio is completely application dependant?

Jeff

-- 
"Keep yourselves far from every form of exaggerated nationalism, racism and 
intolerance."
-- Pope John Paul II