Gmail, Google’s online email system has an interesting take on the storage it gives users. Rather than give out a flat number, like say, 5 gigabytes, Gmail has a policy called “Infinity + 1.” Basically, this means that the amount of storage you get is always growing. Today, the amount of storage each Gmail user gets surpassed 7 gigabytes for the first time.

For some comparison, Microsoft’s Windows Live Mail gives users 5 gigabytes of storage. But Yahoo Mail claims to give out an unlimited amount — as far as I know that claim has never been put to the test. Google originally blew all of the other online email services out of the water when it launched in 2004 with 1 gigabyte of storage. (Some even thought it was an April Fools’ joke because it launched on April Fools Day.) At the time some competing services offered as little as 10 megabytes of storage.

A year later, Google upped that storage to 2 gigabytes, free to all users. Then it decided to put its ever-growing method for storage in place. But users who require more than the current 7 GB can purchase more. It’s $20 a year for 10 GB, $75 for 40 GB, $250 for 150 GB and $500 for 400 GB. But that storage can be used across many of Google’s services, like its Picasa photo service, for example.

Some may think that Gmail’s current 7,168 megabytes of storage equates to 7.1 gigabytes, but the conversion is not done in multiples of 10. Instead, there are 1,024 bytes in one Kilobyte (KB) and 1,024 KB in one Megabyte (MB) and so on… Thus, 7.168 MB equals 7 GB.