[exolab]

The quality of targeting differs greatly depending on

a) the technology used b) how much exposure you have to technology that can capture your interests (or your socio-demographic profile etc.)

If you use Gmail you will find that their ads are usually quite a good match for your interests, because the amount of exposure with Google is huge for the average user, and because they can use semantic contextualization on your mails...

[rogerbinns]

Gmail is not my primary email, and I access Gmail via IMAP only. In any event I don't think what they see would be that useful. My Google Reader usage is more closely aligned with my interests, but I rarely star anything so they won't know the difference between feeds/articles that are genuinely interesting to me, and those that I use just to ensure I am up to date.

The manufacturer of my car has never displayed an ad trying to get me to take it in for a service, or sing the merits of the newest model that hits home for an existing owner. The various credit related ads seem to think I don't know money is fungible, or that I can't count. The various health and beauty products are extremely misguided. The food related ads are beyond stupid. The cell related ones assume that ETFs don't exist. I can go on, and on ....