A colleague who’s really into Google AdWords showed me a great example of personalized Google ads. In some cases, Google shows ads that are related to your previous search queries. It even works when all cookies are deleted and you aren’t signed in to your Google account or whatever. The searches must be executed in the same window, however.

Let’s say I’m looking for the weather forecast. When I search for “weather forecast“, I’ll get these results (click to enlarge):

What if the next thing I’m looking for is a “Holiday to Spain“?

Now let’s see what happens to the ads if I enter “weather forecast” in the search box again?

Hmm, the first ad looks really targeted to me. Let’s see if we can get personalized ads on other queries as well.

My girlfriend’s birthday is in a two weeks, and because I’m a really cheap bastard, I’m looking for a “sale” somewhere.

Oh wait, I almost forgot, I need a new “LCD monitor“:

Hmm, back to the search for a birthday present again. Enter “sale“, hit GO:

That’s 3 really targeted ads. Looks like Google’s getting smarter by the minute…

Update 1: Ben Murphy also noticed it and it seems to happen with AdSense ads as well.

Update 2: Google sent SEL a reaction with some more info about this:
“What you’re seeing is that we look at the user’s previous query and see how well it intersects with the current query. If it’s significant, we’ll use it to help targeting on the current query. We simply look at what’s in the referring URL (every time you load a web page, the HTTP header includes your previous URL as the “referrer”).”