[dagw]

since their customers don't provide funding

That depends on your point of view. I'd argue that the people supplying the funding are the customers and that the work they do and people they help is the service they provide. So if their customers aren't happy with the quality of the service they'll take their money somewhere else, exactly like in the for profit case.

[yummyfajitas]

The problem is the customers of nonprofits often cannot measure the results themselves.

If McDonald's serves me a burger that is inedible, I know about it immediately and can stop patronizing McD's.

If Burgers4Africa distributes inedible burgers in Somalia, how do I know about it?

[stcredzero]

My point is that often the customers can measure the results. The article is worded as if this applies to all non-profits.

[anamax]

> I'd argue that the people supplying the funding are the customers

That definition is inconsistent with 'There can be something like a marketplace where the "customer" pays not with currency, but with their time.'

Charities, almost by definition, provide products/services to folks who can't afford the full cost of said products/services so the charity gets money from elsewhere.

Note that not all non-profits are charities.