For example, PBS Interactive stores 90 percent of its streaming video content in the Amazon S3 cloud. "S3 is brain-dead simple -- you put stuff in it and take stuff out of it," says Drew Engelson, chief architect and senior director of platform development at PBS in Arlington, Va.
In PBS's case, S3 is the origin server for media assets that get delivered via Amazon's CloudFront content delivery network. "We put the high-bit-rate original files on S3 for permanent storage and for ingestion into transcoding workloads. So we'll drop a high-bit-rate file into a particular S3 bucket that is being monitored by a transcoding service," he says. "The transcoding service will pick up that high-bit-rate file, transcode it into our final output format and drop those into a different S3 bucket. From there we can deliver those files through CloudFront."
It would have been possible, but difficult, to stream video content using a traditional infrastructure, according to Engelson. "We're a media organization, with a goal of delivering as much PBS content to end-users as possible. We've simply found that this is one way that makes it easier to do that," he explains.
Success stories like that have helped generate interest in public cloud storage, says Couture. After all, the model does come with considerable positives -- scalability up and down, pay-by-use pricing, vendor-provided management, and software agnosticism. Those qualities, of course, are particularly appealing to lean startups and small and midsize companies, he says.
Gartner is projecting 100 percent year-over-year growth in public cloud storage services for the next five years -- though Couture points out that that's starting from a minuscule base. For 2011, Gartner projects that cloud storage revenue will hit $150 million to $200 million. "That isn't an extensive neighborhood," Couture says.
For example, financial services companies, by nature conservative, generally aren't going to put customer-specific data in the cloud, says Andrew Reichman, an analyst at Forrester Research. But then again, he adds, they tend to be big companies with the wherewithal to build their own data centers cost-effectively and therefore have less of a need to use the public cloud.
When you consider public cloud storage in terms of vertical industries, you have to think about security and risk, says Reichman. "Public cloud storage is certainly getting a lot of attention," he says. "But the questions are about where it can fit down the road. It's not a ready-to-go thing."
Whether public cloud storage providers thrive or wither away may depend on how well they understand two things, Reichman says: how companies in different industries use data, and how important it is for those companies to keep their data secure.
A new crop of cloud providers, including Cirtas Systems, Nasuni, Panzura, and StorSimple, have developed gateway storage products designed to be flexible enough to accommodate enterprises' varying storage needs. In essence, these vendors enable users to build hybrid clouds, using local caches for data that is used frequently, must be accessed quickly, requires tight security, or is otherwise unsuited for the cloud, while sending the rest out to public storage.
"If a service provider can say, 'We know your workflow. We know how you deal with your customers. We know that this data is sensitive and that data is not, and we propose to do a better and cheaper job of holding the nonsensitive data for you,' then it's much more viable for that company to say, 'This offering will meet your needs,'" Reichman adds.