How does Google Mail provide an inbox that is constantly increasing in size?

Because google is constantly growing,
Google is made up of lots of standard desktop pcs, so as they add more pcs, they can give you more space.
I like gmail, its my online backup space, just attach any files you need to keep safe and email them to yourself. :) and you get vertually no spam!

"Google is made up of lots of standard desktop pc's" !!?

Is it?

Where did you get that from?

I think they have bigger servers but I'm prepared to be corrected on that one.

Got a source?

From http://www.google.com/corporate /tech.html copy

"From the beginning, Google's developers recognized that providing the fastest, most accurate results required a new kind of server setup. Whereas most search engines ran off a handful of large servers that often slowed under peak loads, Google employed linked PCs to quickly find each query's answer. The innovation paid off in faster response times, greater scalability and lower costs. It's an idea that others have since copied, while Google has continued to refine its back-end technology to make it even more efficient.

The software behind Google's search technology conducts a series of simultaneous calculations requiring only a fraction of a second. Traditional search engines rely heavily on how often a word appears on a web page."

I very much doubt that google are going to pc world every week to buy a few more £700 pc to add to their network. What this is saying is that google use lots of smaller servers rather than a few large servers.

I think it might also be to offer a viable alternative to Microsoft and to some other companies who expect you to PAY for a bigger inbox.