I get this question at nearly every meeting with a prospective client.  There is still a perception in the business world that data is more secure or reliable on a corporate network than on the Internet, presumably because the latter is connected to nearly every other computer in the world.  Corporate networks were probably more secure and reliable in the 1990's, but Internet data centers long ago passed corporate networks on these fronts.

I ran IT departments at a handful of companies over the years, and although I was proud of our systems, we were always constrained by budgets and staffing levels; meaning we had adequate systems, but never the best systems available.  Internet data centers do not have these constraints and spare no expenses; their networks and infrastructures are truly outstanding.  They can guarantee uptime (99.99%) that corporate networks can only dream of.

We outsource our data center to RackForce Networks, and they offer the following security and reliability features:
    -  A location outside natural disaster zones (earthquake, hurricane, tornado, flood)
    -  Redundant hydro-electric substations
    -  Standby diesel generators
    -  Fiber-optic gigabit Internet backbone connections with multiple Tier 1 providers
    -  Redundant UPS systems
    -  Electronic security systems
    -  In-floor HVAC and GeoThermal heat pumps
    -  A network operations centre with around-the-clock monitoring
    -  Corporate partnerships with IBM, Microsoft and Cisco
    -  etc. etc. etc.

What is particularly great about RackForce is that they are located in Canada (Kelowna, BC specifically).  Some of our clients have expressed concern about data privacy resulting from the Patriot Act, which provides the US government certain abilities to access information at data centers south of the border.  I doubt the US government would ever see a need to access safety management data, but at least the possibility has been eliminated by having our data stored in Canada.