a small to medium sized business jet can easily mount an iridium terminal on top of it, where even the smallest/least capable geostationary vsat cannot.
you can fairly easily integrate iridium into something as small as a cessna 172...
at the minimum iridium will provide the ability to make phone calls to/from the PSTN while in the middle of an ocean on its smallest terminal. go up in terminal size a bit and you get something good for 500kbps of data.
for very large business jets that would be crossing the atlantic or pacific, that's a different market (overlaps somewhat with the same aviation VSAT terminals you would see on a 737-900 MAX)