Possible to choose the topics of advertising?

[dulldull]

What's shown in Adsense is supposed to be driven by the content, but my site has too many different topics and basically any type of adsense is suitable for the site ---- quite a poorly designed website for Adsense, especially the contents are generated by PHP in which Adsense script doesn't read it well.

But from the experience, the ads about the recent financial crisis, free stuff can earn high CTR. Adsense occasionally shows up these ads in my site, but sometimes they also show up very irrelevant and boring ads (like Chemical wholesales, industrial machine ...).

Is there any LEGAL way to change ads matching for a site with vast topics?

[leadegroot]

I think the ads are more targeted per page, rather than the whole site.

The only real way to tweak the targetting is with 'section targetting' - check the help.

Cloaking would be your only other option, and obviously that would be against the TOS.

[wyweb]

Section targetting works. It does for me anyway.

[dulldull]

Thanks for the tips and it seems the simplest way i can do now.
But wait, today's CTR reaches 1% (normal level?) and i think i better wait for one more week before i tried to make any change. (The ads were put only a few days ago....)

[netmeg]

Took me almost 18mos to get really good, targeted ads. YMMV.

[piatkow]

Targetting is at page level but as the page context is being examined by a machine it may respond to words that are just "noise" as far as you are concerned but which somebody is bidding on in a different context.

[LifeinAsia]

Do make sure your individual pages are focused on a topic. If you have all kinds of topics on a page, it will be hit and miss for which keywords the AdSense bot will select to base the ads on. Depending on how much traffic each page gets, it can take days or even weeks before some pages start getting relevant ads.

[jimbeetle]

especially the contents are generated by PHP in which Adsense script doesn't read it well

Don't worry about this. If you view the source when a page is displayed in a browser you'll see that pp outputs html.

Use good page title elements, throw in an <h1>on page title</h1> and, as LifeinAsia says, make sure the page is focused. Ditch any non-topical nav or other content on each page. Might take time, but should help.

[wyweb]

throw in an <h1>on page title</h1>

Another good tip that's often overlooked. Goog loves header tags.

[fredw]

Also, in my experience, I get very good results by having site-related keywords in my urls. So, instead of urls like

www.example.com/200809260100.html

I have urls like this

www.example.com/news/widgets/blue-widgets/200809260100/blue-widgets-recall-announced.html

even though all I really need to generate the page is that 12 digit number. I've found, with keywords in the urls, new pages target correctly instantly, and stay targeted.