Today, Amazon Web Services is a mainstay in the cloud infrastructure services market, a $60 billion juggernaut of a business. But in 2008, it was still new, working to keep its head above water and handle growing demand for its cloud servers.

In fact, 15 years ago last week, the company launched Amazon EC2 in beta. From that point forward, AWS offered startups unlimited compute power, a primary selling point at the time.

EC2 was one of the first real attempts to sell elastic computing at scale — that is, server resources that would scale up as you needed them and go away when you didn’t. As Jeff Bezos said in an early sales presentation to startups back in 2008, “you want to be prepared for lightning to strike, […] because if you’re not that will really generate a big regret.

If lightning strikes and you weren’t ready for it, that’s kind of hard to live with. At the same time you don’t want to prepare your physical infrastructure, to kind of hubris levels either in case that lightning doesn’t strike. So, [AWS] kind of helps with that tough situation.”

An early test of that value proposition occurred when one of their startup customers, Animoto, scaled from 25,000 to 250,000 users in a 4-day period in 2008 shortly after launching the company’s Facebook app at South by Southwest.

At the time, Animoto was an app aimed at consumers that allowed users to upload photos and turn them into a video with a backing music track. While that product may sound tame today, it was state of the art back in those days, and it used up a fair amount of computing resources to build each video. It was an early representation of not only Web 2.0 user-generated content, but also the marriage of mobile computing with the cloud, something we take for granted today.

For Animoto, launched in 2006, choosing AWS was a risky proposition, but the company found trying to run its own infrastructure was even more of a gamble because of the dynamic nature of the demand for its service. To spin up its own servers would have involved huge capital expenditures. Animoto initially went that route before turning its attention to AWS because it was building prior to attracting initial funding, Brad Jefferson, co-founder and CEO at the company explained.

“We started building our own servers, thinking that we had to prove out the concept with something. And as we started to do that and got more traction from a proof-of-concept perspective and started to let certain people use the product, we took a step back, and were like, well it’s easy to prepare for failure, but what we need to prepare for success,” Jefferson told me.

Going with AWS may seem like an easy decision knowing what we know today, but in 2007 the company was really putting its fate in the hands of a mostly unproven concept.

“It’s pretty interesting just to see how far AWS has gone and EC2 has come, but back then it really was a gamble. I mean we were talking to an e-commerce company [about running our infrastructure]. And they’re trying to convince us that they’re going to have these servers and it’s going to be fully dynamic and so it was pretty [risky]. Now in hindsight, it seems obvious but it was a risk for a company like us to bet on them back then,” Jefferson told me.

Animoto had to not only trust that AWS could do what it claimed, but also had to spend six months rearchitecting its software to run on Amazon’s cloud. But as Jefferson crunched the numbers, the choice made sense. At the time, Animoto’s business model was for free for a 30 second video, $5 for a longer clip, or $30 for a year. As he tried to model the level of resources his company would need to make its model work, it got really difficult, so he and his co-founders decided to bet on AWS and hope it worked when and if a surge of usage arrived.

That test came the following year at South by Southwest when the company launched a Facebook app, which led to a surge in demand, in turn pushing the limits of AWS’s capabilities at the time. A couple of weeks after the startup launched its new app, interest exploded and Amazon was left scrambling to find the appropriate resources to keep Animoto up and running.

Dave Brown, who today is Amazon’s VP of EC2 and was an engineer on the team back in 2008, said that “every [Animoto] video would initiate, utilize and terminate a separate EC2 instance. For the prior month they had been using between 50 and 100 instances [per day]. On Tuesday their usage peaked at around 400, Wednesday it was 900, and then 3,400 instances as of Friday morning.” Animoto was able to keep up with the surge of demand, and AWS was able to provide the necessary resources to do so. Its usage eventually peaked at 5000 instances before it settled back down, proving in the process that elastic computing could actually work.

At that point though, Jefferson said his company wasn’t merely trusting EC2’s marketing. It was on the phone regularly with AWS executives making sure their service wouldn’t collapse under this increasing demand. “And the biggest thing was, can you get us more servers, we need more servers. To their credit, I don’t know how they did it — if they took away processing power from their own website or others — but they were able to get us where we needed to be. And then we were able to get through that spike and then sort of things naturally calmed down,” he said.

The story of keeping Animoto online became a main selling point for the company, and Amazon was actually the first company to invest in the startup besides friends and family. It raised a total of $30 million along the way, with its last funding coming in 2011. Today, the company is more of a B2B operation, helping marketing departments easily create videos.

While Jefferson didn’t discuss specifics concerning costs, he pointed out that the price of trying to maintain servers that would sit dormant much of the time was not a tenable approach for his company. Cloud computing turned out to be the perfect model and Jefferson says that his company is still an AWS customer to this day.

While the goal of cloud computing has always been to provide as much computing as you need on demand whenever you need it, this particular set of circumstances put that notion to the test in a big way.

Today the idea of having trouble generating 3,400 instances seems quaint, especially when you consider that Amazon processes 60 million instances every day now, but back then it was a huge challenge and helped show startups that the idea of elastic computing was more than theory.