How does Adsense know what ads to put on search results?

I mean on site search.

[HughMungus]

Sorry if this is a stupid question.

[Sunflux]

Do you mean on *your* site's search results, or on *their* search results?

[HughMungus]

On mine. If I have my own search using, say, PHP, how does Google know what ads to put on the results? I thought the ads are based on spidering, not real-time analysis...?

[Jenstar]

Sometimes it is based on themed ads.

Other times, it goes based upon the fact multiple people have searched for the same thing.

For example, someone searching your site for purple widgets, they might end up with a search result string of [example.com...] The first person who does that search might get PSAs or themed, but the next time someone does the search, mediabot will have visited that URL, and will show purple widget ads to that person.

[ZopeMaven]

From my recent experience with a new site, if this is the first time that particular search has been done (according to the combination of terms in the URL), then you'll get default ads for the result page. A few minutes later, if you do the same search, you'll get AdSense ads based on their analysis of the page.

I think this implies that searches for results with AdSense ads should be performed with GET, rather than POST (this also makes searches linkable and bookmarkeable).

[Sunflux]

Right. For anything done with POST, it will only get the program's URL and will never know what you're actually doing. With GET, it has everything.

Personally, I think POST should only be used where you really don't want the exact URL known, and the spider-friendly GET for everything else. Since I changed my site search engine to another that defaulted to GET, I've suddenly been able to put useful ads on its results page.