Some would say the cctld of the end-users country. This is true if the end-user is targeting locals in their country.
However, if we are talking about an end-user who is targeting clients/users across various countries, and considers themselves "global", and .com is not available for purchase or some other reason, then .net would better suit them. Of course, it is also wise to have the cctld then for defensive purposes.
But to answer your answer question: do you choose .net or .org?
If you are not an organisation/ngo/society, but rather a company offering services which is commercial in nature, then .net would better suit the end-user. For example, it's makes sense for an insurance company to rather use .net than .org (if .com is not available for purchase, perhaps developed) for offering services to it's clients. .org would not suit them well.
And it would be better for a heart foundation to be based on .org, e.g. Heart.org
Some say .net is an "orphan". hahaha! Those dummies who say this, can't even afford .com, and use this "orphan" crap to justify buying .co, .cc, .whatevercrap they believe in or are pumping to others and into their blood stream like crack-domaine.
I doubt they even know where this "orphan" idea originated from. It was Rick Schwartz who said .net is an orphan. He said this many, many years ago, and he was actually justified for saying this because he owned and still owns plenty of great .coms. If I was in his position, I would also be justified in saying this.
But the monkeys who say ".net is an orphan" only say this to justify why they are "investing" (lol) their dough in .co, .cc, .ws, .tv, but are not coming from the same stance as Rick. Rick would not support their reasoning for their "investments".
At the time when Rick said this, "networking" was not that big online as it is today. In fact, it was unknown to many that the internet would evolve in such a way. .Org made sense then, for organisations and still does, and that's why Rick said that .Org had potential as an alternative. But .org does not make sense for most businesses. The internet has evolved, and .net actually makes sense in today's context.
Times have changed. .Net is not an orphan...but if you wanna go there, let us see those great .coms