1. there was this snow season last month and the roads stopped working and suddenly the air prices skyrocketed. (as is now expected), i had to buy a ticket in emergency which i paid 4x the reasonable rate with all websites saying "oops, the fare has increased" trick.
2. many websites did the "just 1 seat remaining" trick and i jumped the gun.
when the next day i traveled, the plane was half empty.
what happens is, travel agents buy up tickets well in advance and then sit on the bookings, they either sell directly or wait for online portals to sell them.
these travel agents having purchased tickets in bulk then say "oh, the ticket is priced $100 on kayak, i will sell it for 95. lets give you some discount" all the while having purchased the same for like 20.
these people are willing to forego tickets because its more profitable to keep the prices high