Man, you guys...
There is one and only one way to make a profit on anything (without coercion or outright theft). One! You take a set of resources being used for one thing, or not being used at all, and redeploy them in a way that causes someone to value the new resource configuration more highly than s/he valued the old configuration. That's it. All other descriptions of how to make money reduce to this general prescription.
"Loopholes" has emotional connotations, but is essentially a way of describing a perceived opportunity resident in a given set of resources. It's all a loophole is, it's all Windoze is.
There are thus two strategies for making money: to redeploy existing resources in a way that realises greater value to someone, or to create new resources. An example of the second strategy is the ballooning utility of internet applications we are seeing today. (Strictly speaking, of course, no new resources have been created since the Big Bang, it's all redeployment. But because the re-interpretation of some resources' utility represents such a quantum leap in terms of what you can do with those resources, it amounts effectively to resource creation.)