[jasonkester]

Not really. If your day job is designing icon sets, then pumping out one more on the side isn't really all that hard. Especially if your day job is designing a client site that happens to need a whole bunch of icons for a client who doesn't consider things like generated IP to be worth protecting.

There are lots of examples of this sort of thing that make it pretty straightforward to take something that you're doing anyway and spin it off as a product that brings in revenue. If fact, the product that pays my rent (S3stat) was exactly that: something we needed in house that turned out to be something other people would pay for.

So yeah, it's probably not anywhere near as much work as you expect. And like people are telling you elsewhere, once it's built, it stays built, and the money keeps rolling in.

[stinkytaco]

Are you kidding? The last think I want to do after I do my day job is more of my day job. I think lots of people feel this way and that's why they find the article valuable, the realization that their extra time can be parlayed into future earning. But yeah, it will take time and work, sometime time and work some of us just can't bring ourselves to do, no matter the future value.