So I assume "park.io" posted the domain for sale and gave the market ample time to buy the domain before snatching it up for them/your selves?
You buying it before posting it is no better than you drop-catching it.
Re:Show HN: File.io – Ephemeral file sharing
by saiko-chriskun on Thursday July 30, 2015 @01:55AM
(#9973343)
you're free to buy the domains yourself? he bought it from the previous owner and has every right to use it as he sees fit, and in this case actually launched a useful service in place of just sitting on it.
park.io doesn't just get domains from drop-catching when they expire. Sometimes we buy them from the previous owner directly. Also, not all sales go through the drop-catching/auction process, for example users can park their domains on park.io and set a "Buy it Now" price for their parked domain, so domains also sell in this way.
file.io was never listed because it never expired/dropped or went to auction. We bought it directly from the previous owner and it was parked on park.io. I have now used it for the service posted here. What you quoted above was said to advertise park.io, and I apologize if it is misleading.