I've done a 'first month free' trial, and let me tell you, I certainly won't be doing that again without /somehow/ confirming identity first. When you offer something as abusable as a *NIX host for free, you /will/ attract abusive users, and I think asking for credit card info and/or charging a dollar or something sounds like a reasonable way to make sure that you are giving this away to someone you can at least threaten to come after if they do abuse the service.
Dual Xeon 2.4, 1GB RAM,
Ok the ram is a little under-generous but can you point me to where I can get a dual Xeon 2.4 (=8 core) server for $40/month?
http://www.joesdatacenter.com/Dedicated_Servers.html
It's a dual Xeon 3.0 with 2G of RAM and it's $60.
http://www.theplanet.com/sand-castle/
I'm fairly certain the first 2.4ghz Xeons came out in late 2001 .. These could easily be 8-9 year old servers.
The labor? Negligible. Most dedicated server providers put their engineering dollars into services, automation, and network capacity. I know a dedicated server firm in San Francisco that pays it's button pushers and hard drive swappers $15/hour, or about 50% more than they would make at McDonalds .. In comparison, the nominal cost of labor for the average task is almost zero. Most dedicated server companies also have banks of systems administrators working in India for $5 per hour to further reduce their costs.
I've run two companies that provided dedicated servers as part of their overall offerings, worked at another two, and consulted for another two. The numbers say: Old Hardware Is Profitable But Expendable.
There are at least a dozen things an operator could do in order to make an offering like this cost them nothing on the books, and on the same note they would still sell these servers in their closeouts/specials section, or use them as freebies in larger deals.