Its actually a good thing that advertisers have my details, so I only see ads for things I prefer. Those are the things I enjoy buying, the things things I like. Just seeing an ad for something that is well suited to me does not mean I will buy it, but I would rather be kept aware of things I enjoy and want then bombarded with background noise of ads for things I don't even want. -- Ads don't force people to buy anything, they simply provide an option. I have never bought a single thing from an ad on facebook (or any other website I can think of)... so go ahead, advertise away and keep my apps free.