The main advantage of using a server load balancer is that the clients don't really care about a load balancer. Concretely, all the clients will use the same endpoint (let's say, quote-manager.demo.packt.com) and the load balancer will distribute the requests without requiring any knowledge of the clients. This is very important in terms of the infrastructure, since you can update your infrastructure without notifying or updating the clients (which can be impossible if not owned by your own system).
For instance, if you start with two machines and decide to add a third one a month later because you get more load or to support the black friday additional load, then you will just register this ...
