Are you leasing your own collocated hardware or are small businesses paying you on retainer as a server admin?

Leasing my own collocated hardware that was originally purchased for a different task but were no longer in use

Nice. So if it's going so well, why don't you just buy some more servers and lease them out as well?

Work really doesn't scale linearly with servers with this type of business. I've known my current tenants for quite some time and they aren't "needy" or problem users, which makes my job easier.

I'd also either need to purchase a new cabinet or move into a cage -- which is not really an upfront cost (or the headache of contract negotiations) I want to take on for a hobby business. In either case, I'd have to start running my own switches (and god forbid router) and while I roughly know how to administer both, those are better left until I have more time to devote.

On the flip side, I have toyed with racking up a few 6U blade servers (~50 blades total) and renting those out as unmanaged, 0-support servers. The problem here is its a race to the bottom with blades and I'm no Softlayer or OVH and can't buy these things at hefty discount. I have worked out the math and after the first 3months, if I sell at least 60% of the blades I'll be paid off and the margins are significantly higher than my current servers.

I do like the idea of being a remote system administrator, but the trust issues seem to scare people away.

(Though I realize you're doing more than that if you're renting out physical boxes too.)

You'd be surprised how trusting people are, I'm explicit that nothing of great personal value or import should ever be stored unencrypted on these since at the end of the day I hold the keys to the proverbial castle. Quite a few of my customers are people I know from BBSs I used to and still do frequent. One even hosts a few BBS servers.

On the whole, I could probably net in the 11-15K range per month if I expanded but that requires a lot more work and I'm not sure the money justifies it. At the moment its a (usually) enjoyable hobby that helps me keep current in sysadm-land and make some money at the same time

Indeed, I personally am looking for a nix admin to help me setup/secure my personal Ubuntu server. Finding someone I can trust is a huge battle.

This is usually the point where I volunteer ;)