>>pbrw+(OP)
I might be in the minority here but I personally find personalized ads useful, and am far more annoyed by ads recommending products and services completely irrelevant to my interests and/or needs.
(The latter still account for the ads I see most of the time, unfortunately.)
>>imafis+8O1
Sellers and marketers don't want you opting into their market (eg. by checking a box that says "I want ads for computers"). They want to target their customers with fine-tuned, data-driven assumptions. Age, gender, income, interests, career...
This is the value Facebook delivers (targeting and measuring), and it's about to go up in smoke.