Originally Posted by RealHJ

With UA you couldn't hold multiple conflicting tickets - UA auto-cancels all but one conflicting, or even close-in, reservations within hours. But anyhow, that's beside the point..

The impact of this is impossible to know, but with dynamic pricing it's not just a binary yes/no availability, there is the added complexity of the algo that does the dynamic pricing in play. There is definitely a fair amount of this going on, as JL flights now by and large are gone if not in seconds then in minutes of release at the normal level, but it's not uncommon for flights to become available again hours and sometimes days later. It wasn't like that previously; this is fairly new.

My biggest concern is that this being widely practiced could very well result in JL going full-on dynamic and never releasing any seats at the normal price, at least not at T-360, in order to eliminate the shenanigans of flights held, or booked, and then cancelled not long after. It's unlikely to go unnoticed for long..

The other possibility is that it may become necessary to use a pay service that tries to grab your flight literally within milliseconds of the availability going up, if too many are competing for it, as there's no way for a human to complete the process fast enough when competing against a machine. Or some 'commercializing' this and profiting off it (holding or booking all flights at T-360, then releasing it when you pay them their 'fee' to 'get you' the award). Such use of bots is again likely to result in adverse changes that are going to impact everyone.

Point being, this is going on, one person is not going to make a difference, but it being seemingly widely practiced is not good and is likely to, sooner or later, lead to bad things (adverse changes, full-on dynamic, or JL becoming like HA is and randomly releasing seats at various dates out, then taking it away again, which makes one search literally many 100s if not 1000s of times for a desired flight over months, as there is a real chance normal price inventory may be - just may be - released, at some random point in time).