Here at Jimnio, there is one thing we think of first. Can Software or Site we are developing handle going Viral or an Uptick?
With this in mind we offer tactics know as load balancing for online resources with Secondary DNS and multiple others if needed.
This requires Database Replication between servers unless you pull from one DB on both sites but it still needs to be replicated in case a rack in a data-center goes completely down.
If you have concerns that sells might be lost due to frequent outages with you hosting company contact us and we can setup you current system with the tools and plan you need to stay up and running.