Sign ups were directly correlated to revenue, at least in my case, and likely most others, such as in @joegahona's comment about publishing. That is to say, the customer satisfaction decrease in popups did not decrease revenue, and that is assuming there even was a satisfaction decrease at all; again, most technical users vastly overestimate how many people actually care about popups, most non-tech people simply click the X to make it go away, and a percentage of all visitors will sign up.