One of the great things about cloud computing from my perspective is the concept of scalability – or elasticity. This is the ability to rapidly add more resources to your system as needed. Let’s say you run an online store and for 11 months of the year you can comfortably run your website with only a couple of servers. But you know that every October demand goes crazy and your web servers are overwhelmed. In a traditional world where you host the website on your own gear (or even outsource that), you could throw more servers at the web site. Which is great in October, but the other 11 months of the year those servers are then under-utilised.
Or consider another scenario – you’re a small startup who has built an online app and clearly you’re starting out small. If the demand for your app goes through the roof in a very short time, you’re not likely to have the funds (or the people) to quickly bring another 100 servers online.
If you had built your online app from the start to be hosted in the cloud, then scalability is easily met. You can benefit from the elasticity that comes with the cloud and just turn on the tap for more resources as you need. Of course you’re paying for it, but if demand dips you can turn them off (perfect for the once a year big sales event). It’s also great if you’re unsure how long the demand will be around for – you’re great app could just be going viral for a few days. By the time the servers have arrived the demand has gone away and you’re left with a bunch of shiny hardware doing nothing.