Google is testing AdSense-related programs intended to give advertisers more control over the types of ads that appear, and is also involving publishers, allowing them to send "signals" about their website so that ads may be better tailored, reports DM News, citing Gokul Rajaram, a group product manager for AdSense.

AdSense already uses site content info, such as headlines and font sizes, to generate ads, but the pilot programs would let advertisers tailor ads based on users' demographics and other, yet-to-be-determined signals. For example, "They could send us a list of topics that users of this site are interested in," Rajaram said.

Also, as earlier reported, Rajaram confirmed that AdWords is testing a new ad size, with ad copy containing up to 200 characters instead of the previous limit of 95 characters - or about 10 more words.

"Our system automatically makes a decision on whether to show the longer or shorter creative, based on what is performing best of the advertiser," according to the Google rep.

More information could increase conversion rates, Rajaram said. Search analysts say longer ads might be less profitable for Google.

"Google will be less likely to use the longer creative units, except perhaps across the top of the page, because Google is usually more interested in giving searchers more choice down the right rail," Kevin Lee, chief operating officer of search marketing firm Did-it.com, is quoted as saying.