Back when I was writing software for PCs, it was pretty common to see licenses offering some program free "for noncommercial use" or some similar wording. The basic idea was that if you got people using some application at home, maybe they'd want to use it at work too--and then they'd buy a commercial license. Besides, very few of those home users were about to send you a check anyway. It's a little bit like using an open-source business model to build volume and awareness with free, unsupported software and then make money from support contracts when a company wants to put the software into production.
There's a difference though.
No widely used open-source software license that I know of makes a distinction about how the software is going to be used. Rather, open-source licenses concern themselves with essentially technical details about how code is combined with other code and what the resulting obligations are with respect to making code changes and enhancements available to the community. But none of the major open-source software licenses restrict use to schools or personal PCs or anything like that. (One could argue that the new GPLv3 license's clauses concerning digital rights management come close to being a sort of usage-based restriction. That's one of the reasons that Linus Torvalds hasn't been a big fan of GPLv3.)
This is probably a good thing. Especially in today's world of interlocking personal and professional lives, defining where "noncommercial use" begins and ends can get extraordinarily tricky.
This was brought home to me last week while putting together a presentation that uses some photographs posted on Flickr.
By way of background, I was searching for photos licensed under Creative Commons--a sort of counterpart to open-source software licenses that is intended to apply to things like books, videos, photographs, and so forth. There are a variety of Creative Commons licenses worldwide (e.g. these are the choices offered on Flickr), but for our purposes here, one important distinction is between the licenses that allow commercial use and those that do not. A noncommercial license means: "You let others copy, distribute, display, and perform your work--and derivative works based upon it--but for noncommercial purposes only."
At first blush, this seems intuitively fair and reasonable. Many of my own photographs on Flickr are licensed under a noncommercial Creative Commons license. It just feels right. Sure, you can use one of my photos on your Web site (with proper attribution, as required). But I can't say that I'd be especially thrilled to learn that someone was off hawking my pics on a microstock site or selling posters without giving me anything back. Thus I, like many, chose a noncommercial license.
But start squinting hard at the line that separates commercial from noncommercial and it starts to get fuzzy in a hurry. Consider the following questions. Are any of these uses truly noncommercial?
What if I have some AdSense advertising on my Web page or blog?
What if I actually make "real" money from AdSense?
What if I put together an entire ad-supported Web site using noncommercial photos?
What if I use the photo in an internal company presentation? (All companies are commercial enterprises, after all.)
What if I'm using those photos as "incidental" illustrative content in a presentation I'm being paid to give? (This was my case.)
What if I print a book of these photos but only charge my cost? What if I cover my time at some nominal rate as well?
And so forth.
This isn't a new question. I did find a discussion draft of noncommercial guidelines, but for the most part it seems a dangerously ill-defined question in an environment where individuals have so many opportunities to micro-commercialize. Sure, the average blog's AdSense weekly revenues won't buy a cup of coffee but that's a difference of degree and not kind from someone who makes $100 a week or $1,000.
I suspect that noncommercial Creative Commons exists because it appeals to an innate sense of fairness. As such, people who wouldn't license under a broader Creative Commons license will use this one. In short, noncommercial Creative Commons is convenient. That doesn't make it necessarily good.
(By the way, I concluded that I would probably have been OK using noncommercial-licensed photos because they were incidental to the topic that I was presenting. However, to be on the safe side, I stuck with photos that were explicitly licensed for commercial use.)