To play devil's advocate, advertising is a social good, and better advertising is even more of a social good.
How many times have you heard someone complain, "I just bought a desk lamp, and now I'm getting loads of ads for desk lamps. Don't they know I don't want another desk lamp?" And surveys back it up -- people would largely rather the ads they see reflect the things they're interested in. Because a well-targeted ad is good for the viewer. Sometimes they want the thing, and they buy it, and their life is improved.
If I'm statistically more likely to buy a particular item because of some demographic I belong to, and you have my demographic information, by all means use it to decide which ads to show me.
Maybe you having that information is a breach of my privacy, but if you do have it you should at least use it for something that'll benefit me.
How many times have you heard someone complain, "I just bought a desk lamp, and now I'm getting loads of ads for desk lamps. Don't they know I don't want another desk lamp?" And surveys back it up -- people would largely rather the ads they see reflect the things they're interested in. Because a well-targeted ad is good for the viewer. Sometimes they want the thing, and they buy it, and their life is improved.
If I'm statistically more likely to buy a particular item because of some demographic I belong to, and you have my demographic information, by all means use it to decide which ads to show me.
Maybe you having that information is a breach of my privacy, but if you do have it you should at least use it for something that'll benefit me.