20M users but not a single server, the popular web platform for promoting social change, passed the 20-million user mark last month and expects to surge past 25 million later this year. And yet it runs not a single server in its offices.

“We run nothing in house. I don’t have a single rack in this place. We don’t even have a PBX,” said Kyle VanderBeek, manager of infrastructure for the 6-year-old San Francisco-based organization. The IT team is similarly lean. Four people on the 150-person organization handle loosely-defined IT functions but there’s “zero staff” dedicated solely to IT. Tasks around things like email are shared by VanderBeek himself and HR and other operations people.

Riding the success of online petitions

The operation zoomed to prominence when the parents of Trayvon Martin, the teenager who was shot by a neighborhood watch volunteer, used the site to launch a petition seeking an investigation. That online petition logged 1,000 signatures per minute so it knows a little something about scaling.  To keep up and running, it looks outside using software as a service tools for in-office functions. It runs its backend analytics and business intelligence on Amazon(s amzn) Elastic Map Reduce (EMR) and front-end web analytics on Google(S goog) analytics and MixPanel, said Tim James, software engineer.

The key to success is choosing the cloud services best suited for a particular job and if things change, being able to move. There’s not a lot of orthodoxy. “Six months ago what we really needed was faster disk speed. At that time AWS [Amazon Web Services] did not offer a pure high-speed I/O system so we talked to a number of vendors and found that hybrid hosting at Rackspace(s rax) worked best so we moved our primary database hosting there,” VanderBeek said.

The company still uses Amazon for archival storage, to serve up its pages as well as Simple Workflow Services (SWS),  and the aforementioned EMR for back-end analytics. “We could have gone all-Rackspace using its CDNs and other offerings but we have 20 million users and are getting more international all the time so we looked at all the CDNs and sticking with Amazon made sense — it has 27 points of presence on every continent. It fits our needs and our audience better than other companies.”

Users: Keep your deployment options open

People who deploy workloads to cloud have to evaluate just how much they will lock into a given platform’s higher-level services. There is controversy even among AWS users about whether it’s wise to use Amazon DynamoDB or even SWS because that makes it harder to move.  “If you’re on DynamoDB or RDS {Relational Database Service] that move is not as easy– it’s more a hidden software stack that they manage themselves that makes a transition off more difficult,” he said. engineering staff.

He is not concerned about’s use of EMR or SWS however. “Migrating would not be difficult in that we are bound to simple workflow for the control of our processing but we don’t have to run any of the processing or storage itself in AWS,” he said.

The important thing from the end-user standpoint is to steer clear of religious wars — to keep an open mind and to run continual cost-benefit analyses of different deployment options. It’s important to keep tab son new features and functions of the platforms — something that could be a full-time job given the pace at which the cloud providers — especially Amazon — updates its options.

And, keep in mind that while cloud is excellent for many jobs there may be times when on-premises IT is the best option. “I may actually order some servers next week,” VanderBeek said.  “When you look at economies of scale, every once in awhile you can find a business case to make a capital outlay and save money.”

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Feature photo courtesy of Flickr user Ryan Resella