According to the Optus press release [1] this will a service Starlink sells to phone companies to extend their coverage. This is a big deal in Australia because 60% of the land mass still has no standard phone coverage. Telstra has the best rural phone coverage by far, so if you frequently go to the wilderness you use Telstra. If Starlink lives up to the promises, I suspect a lot of people will be switching from Telstra to Optus over the next few years.

[1] https://www.optus.com.au/about/media-centre/media-releases/2...