I’m probably not the first person to think this, but is advertising in Opera worth it?

The only people who see the ads are those who don’t pay the $39 to purchase the ad-free version.

Okay, okay, I know that people have different priorities and that someone who dosn’t spend that money on a web browser may spend it on something else instead. And indeed there are some users who buy the full version but keep the ads switched on as they like them.

Presumably this last group mostly keep the Google text ads switched on as these -

• Take up far less GUI real-estate than the banner ads
• Provide ads related to the contents of the page being viewed

The Google text ads are drawn from the same database as the AdSense boxes that people can include on their pages. But when you visit a page with AdSense enabled page you don’t always get the same ads in the two locations.

On the subject of AdSense, the following one line of CSS in a user stylesheet will hide them entirely:
iframe[name="google_ads_frame"] { display: none;}