The connection we rely on for our communications with the outside world is so important in today's businesses. Applications such as Email, VOIP and E-Commerce Web Sites are heavily relied upon depending on the business you are in. At a minimum we all expect Email to be up and running and most of us use Email as a main mode of communications.
We could go out and get a second Internet connection as a backup in case the primary went down, but that would leave us with an expense for a secondary connection that is not being used and would not help us with services that come in from the outside since they are "bound" to an IP Address that is used with the providers circuit that is currently down.
We have a solution that is a hardware based appliance, the cost is about the same as a firewall and it enables your business to use two Internet connections for outbound traffic, provides policies for the outbound traffic and enables inbound traffic to continue to work in the event one of the connections fails. This device becomes the "authoritive" DNS for any domains you host. For instance - if your domain was called xzy.com and you had 2 Internet providers for redundancy (provider1 and provider2), you could utilize this device and use the bandwidth from both connections everyday, while enabling your incoming services such as Email and Web Sites to continue to work in the event you lost one of those Internet connections. In the end you mitigate your risk of an outage, utilize both connections you are paying for and add a level of redundancy for both incoming and outgoing traffic.