Airfares - good news/bad news

I've also seen articles that say that the type of computer and the browser you use for the search are among the many things taken into account by the dynamic pricing systems -- e.g, if you do the same search using Safari on a Mac and Firefox on a PC, you will get different pricing.
Cookies and various trackers from the aggregator sites certainly do look at your browsing history, and when they see that you like a particular route, that is factored into the price it shows you.
I see this often regarding hotel rooms on Expedia and apartments on AirBnB -- I have some extensions installed that slow down the refresh rate of my browser, so I can see the prices shift, usually upwards, as the page elements redraw on the screen.
I actually recovered some money once from Expedia under their best price guarantee with a screenshot that proved that they charged me more for an (exactly identical) room reservation than they had listed in their own search results --
they charged more during checkout than they listed with the ~select this choice~ button.

I have also read that if you delete cookies on your computer after first doing a search and then do the exact same search again you will get different results. I often do car rental searches, primarily in Hawaii, and I get different prices from different sites. Most of the time the car rental companies have the highest prices when checking directly with them. Unlike hotels, where I check prices elsewhere on the web, I book directly with the hotels themselves. That is due to piece of mind in case I show up at a hotel and they do not have my reservation or other choices.

The "cookie myth" rises again. That would explain why yesterday my upcoming ATL BOS was $311 and today it went down to $275. The airline raises rates when I check a lot.... Or do they (And I did not delete cookies or any of that other useless nonsense)

You may call it the "cookie myth" but I have seen it in action. I often stay at Yotel in NYC. Yotel lowers the price of rooms available as that date approaches. If I use my home computer the price drop will stop at a certain level and not go any lower. IF I go to another computer the price continues to drop. I reserve the lower price and cancel the previous reservation. Luckily, I teach at a school with a large computer lab and have many terminals to use and get the lowest price. I have reserved rooms at the Yotel in NYC for $139 a night including coffee and muffins in the morning.

John,
Maybe it works with Yotel, but I have never seen proof it works with airfares. I think a lot of it is "I checked today and the airfare was X and then it was Y" but when people have actually done some digging the truth is the available "cheap" seats sold. AIrlines only release a tiny amount of seats at the el cheapo fares.

Also I see this happen when people originally check for 1 traveler. "When I put in my party of 6 the fare went way up, they are tracking me" Probably not. What happeneds is the airlnes fare bucket for the "cheap" fare didn't have 6 tickets. The way the airlines work, if you need 6 tickets and they have 1 at $800, 2 at $1,000 and 10 at $1,200 they don't try to sell you the $800 and $1,000 but move all 6 of you to the $1,200 bucket where they have 6 tickets to sell.

And I know it doesn't work that way with other hotel companies and I have booked and rebooked some recent reservations about 10 times as the rates dropped! LOL!