Actually, wikipedia does a great job of outlining the rationale.
- Edge application services significantly decrease the data volume that must be moved, the consequent traffic, and the distance the data must go, thereby reducing transmission costs, shrinking latency, and improving quality of service (QoS).
- Edge computing eliminates, or at least de-emphasizes, the core computing environment, limiting or removing a major bottleneck and a potential point of failure.
- Security is also improved as encrypted data moves further in, toward the network core. As it approaches the enterprise, the data is checked as it passes through protected firewalls and other security points, where viruses, compromised data, and active hackers can be caught early on.
- Finally, the ability to "virtualize" (i.e., logically group CPU capabilities on an as-needed, real-time basis) extends scalability. The Edge computing market is generally based on a "charge for network services" model, and it could be argued that typical customers for Edge services are organizations desiring linear scale of business application performance to the growth of, e.g., a subscriber base.
Also the underlying virtualization or even operating system is less important than the application itself. But the question is what is "the" application?
One such application ideally suited to this sort of edge based deployment architecture is a web cache such as Squid or Varnish as well as a selection of proprietary options. The interesting thing about web cache software in general is how it could be used in parallel to a series of random (untrusted) regional cloud providers. Moreover these caches don't necessarily need to worry about the security, performance or even SLA of a given provider; the location and connectivity is really all the matters. These local cloud services may be viewed as transient (see my post yesterday Random Access Compute Capacity) Meaning, location is more important than uptime, and if a given provider is no longer available, well, there are potentially dozens of others near by waiting to take up the slack.
It will be interesting to watch this space and see what kind of new geo-centric apps start to appear.