For some users this might be true, but not for everyone- whether the advertisers realize it or not. I refuse to buy anything from an ad. If I want to buy a widget and happen to see an ad in the search results for the widget, I'll then refuse to buy the widget because I saw an ad for it. I block every promoted tweet, and enable as much ad blocking as I possible can on all of my devices. I am probably worth a negative amount to advertisers because seeing their ads actively makes me disinclined to buy the product.
On the other hand, I realize that services cost money to build and maintain, and if the subscription came with ad-free (and data-mining free! "ad-free - same great ad-tech data-mining flavor" doesn't count) I would definitely subscribe.
