“08:20 Adam loves Gmail. Great because of the large storage space available. Works well for receiving audio comments. Also loves search based e-mail. As of today, Adam’s quota is 4GB.” – Adam Curry’s show notes for The Daily Source Code podcast, Daily Source Code 248

$3.42 worth of excitement?
Hey, I think that Gmail is great too! But I thought it would be interesting to put this in perspective in terms of IT economics.

Google has given Adam Curry, Podcaster Extrordinaire, 4Gb of storage. Around here you can buy a 200Gb external USB drive for about $0.85 USD per Gb. Just how excited should you be about a $3.42 service?

Now, Gmail must be using a fault-tolerant storage architecture that likely involves mirroring (2x the number of disks required for a given amount of data) and/or RAID-3 or RAID-5 (roughly an additional 30% space required for the parity data necessary to recover from a failed disk).

So, the 4Gb of storage may require as much as 6Gb x 2 = 12Gb and these large arrays are made up of individual disks that are significantly more expensive per unit than the disk in my local computer store (faster spindle speed of 15K versus 7K, larger buffer, faster interface). But an efficient storage area network (SAN) based on serial ATA disks (SATA) or even a directly attached storage array (DAS) brings costs down a lot – even after software and management costs are considered.

This is not a rigorous analysis, but my guess is that Adam’s 4Gb. is costing Gmail less than $6 USD per Gb per year on an efficiently utilized SAN. Ok… that’s $24 or $2 per month. Add bandwidth and overhead costs to get the full picture.

Alternatives to Gmail for the enterprise.
For business, there are commercial alternatives to Gmail. An enterprise may chose to dispense go to a private online mail service. Such services carry no advertising and can offer the same storage and search capabilities. To maintain the organization’s brand they will use your organization’s Internet domain name.

Another alternative, if your organization is large enough, is to run your own web-based mail server (and I’m not referring to Microsoft’s Outlook Web Access, OWA).

But even for large businesses, there are good reasons to outsource mail to a service that will not only provide superior search capabilities, but also will provide records management and archiving that will comply with government and other legal requirements for data retention and retrieval.

I’ll have more to say on the requirements of enterprise e-mail another time.

What is Adam worth to Gmail, anyway?
Getting back to Gmail: For Adam, the search facility is worth a lot. That’s really Gmail’s added value for him. Of course Google expects to make money on Gmail accounts through advertising. That’s not my area of expertise, but I’d be interested to hear how much a power user like Adam is actually worth to Gmail… not counting the promotional factor of regular mentions of the Gmail brand in The Daily Source Code podcast.

Cheers!
-pmh