This article offers some info about Google's adsense technology...
http://www.nytimes.com/2006/01/16/technology/16ecom.html
Google.com and the company's foreign search sites contribute more to Google's bottom line than AdSense, because for every dollar the company brings in through AdSense and other places that distribute its ads, it pays roughly 78.5 cents back to sites like Digital Point that display the ads.
But in some ways, search advertising has a more limited horizon, since the number of advertisements a company can display is limited by the number of searches its users conduct. Internet users continue to increase their reliance on search sites, and Google in particular, but the rate of growth is in the single digits.
By contrast, millions of small sites have not yet signed up for Google's AdSense program, which was introduced in 2002. AdSense quickly gained a following among bigger companies with an online presence, like the Weather Channel, as a way to supplement their advertising deals and populate more obscure pages with paid ads. But as more small sites use the Internet to post photos, journals and other material, the number of pages that can carry new Google ads is growing quickly.
That's what makes AdSense one of Google's most compelling long-term bets, said Charlene Li, an online media analyst with Forrester Research. "I've called Google the one-trick pony for a long time, and for the most part they still are," Ms. Li said. "But they really see AdSense as the next frontier."
To that end, the company has refined the program significantly, with various features intended to attract more advertisers and publishers. For instance, as of late last year anyone who created a blog with Google's Blogger service was automatically enrolled in the AdSense program.
"Before that, it was quite painful to figure out," said Gokul Rajaram, the business product manager for AdSense, "so over the last few months we've seen a sharp uptick in bloggers using AdSense."
For AdSense advertisers, some of the more significant improvements began last June, when Google started allowing marketers to select vast groups of sites on which to advertise, as Paramount Pictures did last year when it chose 100 small sites with hip-hop-oriented content to promote its movie "Hustle & Flow."
Late last year, Google also gave advertisers the ability to display graphical ads on sites within the AdSense network of publishers, as well as the ability to pay different (typically lower) prices for AdSense ads than those available on Google.com. The company will not disclose how many advertisers have joined the program - "thousands" is all it says - but analysts said marketers were quickly warming to it, thanks in part to the recent upgrades.
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That last paragrah says that Google allows graphical ads now "within the Adsense network" (not sure what that means)... has anyone seen these graphical ads?
