With regards to NetSuite (or any specific system), I think the ability to hire temp to be a sysadmin has a lot to do with how far "outside the box" the company's implementation has become over time. I can probably walk into any company that's using plain vanilla netsuite and get up to speed in a couple days. The compounds quickly with every customization, integration, etc. I've been at my current job for over 6 months and I still can't figure out half of what they've done over the previous 4 years (and I have 10 years experience). Mostly because nothing was documented by previous admin (who wasn't really an admin), nor by consultants they hired. And don't even get me started on the lack of documentation/communication by NetSuite's own "Professional" Services.