I have another idea. It seems that the types of ads have changed, and they're taking longer to load.
We also get the once daily pop-up showing up multiple times a day (at least I do).
When IB purchased FT I remember posting that they were going to want to make money.
Well, this is one way. Sell more and different types of ads that take longer to load and get the core participants to pay $12 to browse ad free.
I know there are 2 ads - the Visa and Hilton, plus a survey pop up that moves around the screen that lock up my browser.