Pop up make it too hard to enter information, creates mistakes that cost money
It's too difficult to complete a search or transaction because of the constant pop ups and the lengthy time it takes to click though all the upsells. It interrupts you as you try to enter data, and even led to an error in entering passenger data by covering the screen I was trying to complete. This creates fees to fix the mistakes the website contributed to. This may be a design choice, essentially a kind of scam.