Flow's model isn't directly as an application, I suspect, but rather a browsing engine. Since the article mentions set-top boxes, that means deploying to fixed hardware which is usually the case for things like integrated browsers on TVs, consoles, and digital billboards or the like. And possibly video game UIs, like Coherent Labs's software.
So presumably one would license the engine to use in their device or game and integrate that cost on the end product, rather than a user explicitly paying $X to Ekioh.
One possible approach here could also be dual-licensing under both something like the GPLv3 and offering commercial licenses. That way you get the advantages of being FOSS, but also become able to sell the application to system builders.
So presumably one would license the engine to use in their device or game and integrate that cost on the end product, rather than a user explicitly paying $X to Ekioh.