Here’s a thoughful observations from YieldBuild after attending the the OMMA conference. The issue is whether you can do too much targeting of your advertising and scare folks away by being “creepy”.
Although we’ve only begun to scratch this surface I suspect that it’ll be dependent a lot more on the individual than on the targeting mechanism. For example I don’t really mind Google “reading my titles” and offering relevant ads to me as I read my email, though for some this is clearly a major invasion of privacy. (What? You didn’t realize Google is reading all your titles and possible your content, though I’d guess they dont’t do that for liability reasons alone)