Currently hosting is our second biggest expense (after payroll). The question of buying hardware or buying your own is probably a common dilemma for SaaS companies.
At the moment, I am not leasing rack space from the co-lo, just their machines so we can't install our own or customer-supplied hardware. Given our current hosting requirements and the size of our company, leasing machines makes many things easier on our end.
Keeping similar hardware and software configuration across all servers (we have seven) simplifies administration (provisioning, backups and patches).
Any hardware failure is the responsibility of the hosting provider and they handle it within hours. This also means we do not have to stock compatible replacement parts for our machines.
The hosting provider staff is very knowledgeable and periodically assists in troubleshooting issues with system configuration. This option would not be available if we had our own machines.
If we need a new server, their provisioning time is under an hour.
I upgrade to new servers every few years so leasing is slightly cheaper than renting co-lo space, and paying for bandwidth. I also get the tax deduction immediately rather than have to depreciate.
Delegating the installation and maintenance to the hosting provider allows us to put servers in several geographically separated locations (we have servers in California, Virginia and Texas).
At some point though the cost to lease does offset most of the benefits. What are your experiences? Has anyone switched from leasing to owning (or vice versa)?