As far as I understood the license the <i>primarily</i> is a very important. I had some discussion at work some time ago about Winsplit Revolution, which is licenced under CC:BY-NC-ND. They even have a statement in the Winsplit FAQ:<p><i>Can I use WinSplit at work ?
Of course you can ! The actual licence's "non-commercial" term just means that you can't directly make benefits with WinSplit Revolution. For example, you can't include it in a commercial package of software that you would sell. But as it is a freeware, you can distibute it freely as often as you want.</i><p>The primary goal of using Winsplit is <i>'helping us make money'</i> (by helping us do our jobs easier), which only slightly differs from <i>'making us money'</i>. The only way it could (primarily) <i>make us money</i> would be if we sold it or if we would put a download-page up only to collect ad-revenue.