srx, I don't believe a lot of money was paid or some "high class CG stars" are backing it as you put it. It seems many stumbled into it and almost all have come from the Vray background. That is why it still has a small and humble niche but steadily growing base, most of them seasoned Vray users - just like how Vray started small and pushed through to mainstream over the years.
One of the reasons why so many of these VRAY users make the switch is because they swear by the ease of use to get a very high quality render instead of pissing around with a thousand VRAY settings that have to be tweaked like crazy to come to something decent. Corona almost has the same Keep It Simple Stupid philosophy as Sketchup but with insane quality. It's hard to say that of VRAY. The beautiful thing is that they started like that and expanded on it. It is not like Windows 10, where they come up with an insane beast with layers upon layers of cancer on it and slap a new skin on it that is supposed to simplify things, but ends up making it slower and dumber.
Look, I don't own a copy or license of Corona, nor am I promoting it or helping them promote it. I love the ease of Twilight Renderer though though it is CPU based, and I believe I am fair when it comes to judgement of these rendering engines. I thought I would just settle with my bought versions of SU Podium, but that's history now after Twilight, which apparently is also based on Kerkythea. But this is all old tech and older algorithms, so I am a fan of better and improved algorithms that don't require people to buy fancy schmancy hardware and crazy GPUs to perform simple tasks.
With this remarkable algorithm I can now render from a lower end laptop to get the same speed and results as a souped up GPU machine with a GPU based renderer. I was super excited when this announcement was made and I formed a small part of that vote to make it happen.
Also a couple of long timer guys like Pilou and Solo kind of have seen me around in a past life, lamenting about the lack of adequate rendering quality and speed that most of the renderers seemed to produce. I gave up after purchasing Podium and stuck with that for awhile. Only the mid of this year I only ever heard of Corona and did the homework... and boy, has woken me up to the art of the render again.