The idea behind cloud computing is that your solution can scale to an arbitrary number of nodes, which is handled by the cloud provider. The advantage of the site working in the cloud is that during high load you can easily add servers and scale horizontally. Unlike traditional web hosting, where you buy new servers and potentially own them forever, in the cloud you only pay for the resources how you use them. If you need to temporarily scale, you pay only for the servers as much as you need, then when you zoom out, you do not need to continue to pay for expensive equipment that just sits idle.