Planet operates imagery satellites, and as far as I know that's the bulk of commercial data _produced_ in orbit that needs to be downlinked. Other commercial services that could include radar data (ICEYE, Capella), ship/plane monitoring (Spire, Iridium NEXT), or high-latency low-bandwidth data (think devices out in the field, on vehicles, with relatively light telemetry and/or control needs). Telecom is usually "bent pipe" (think dumb repeaters) and not any kind of store and forward setup that would use this.
In the future, I could see some broadening of the field with more tech demo/development that needs dedicated hardware, and the possibility of commercial experiments run in an automated orbiting lab downlinking data.
Of course, all of those also need what's called TT&C (Telemetry, Tracking, and Control) links, which I've nearly always seen on a separate physical radio. That tends to be a less demanding link, and more likely to be able to make use of something like this IMO.
> Could you give some ballpark numbers and breakdown of the costs involved?
Unfortunately, I very much cannot do more than point at what's already public; that's one thing Planet is very tight-lipped about. The idea that one spends about as much on launch as on the hardware they launch seems about right, you can go see what Rocketlab[1] and SpaceX[2] quote as prices. I'm sure you can imagine there's still a lot of negotiations once you're talking about big stickers.
Someone's already mentioned SatNOGS[3] further down in the comments. They seem neat although I haven't looked too much into them yet. Schools are spinning up a surprising number of satellite projects, and amateurs are already developing hardware, running tests, and practicing with radioing the hardware that's already up there. I'm sure it's not far from some pitching together on the group buy of a very small amount of launch space.
> Is there some secret cabal of millionaires and billionaires that are really into space?
Yes, but they're not so secret. Elon Musk, Jeff Bezos, Richard Branson, off the top of my head. DFJ and Data Collective are VCs that have been fairly interested, I'm sure there are more looking to get a piece now.
[1] http://www.rocketlabusa.com/book-my-launch/ [2] https://www.spacex.com/about/capabilities [3] https://satnogs.org/
