Paid inclusion was how a lot of search engines worked before Google came on the scene. Companies would pay for chances to be included more highly in search results — not separately to the side in clearly marked ads, but directly within results.
This kind of focus on short-term revenue over quality search results opened the way for Google to come in and crush the competition.
In the now infamous "Don't Be Evil" section of its IPO filing, Google came out against paid inclusion:
We will do our best to provide the most relevant and useful search results possible, independent of financial incentives. Our search results will be objective and we will not accept payment for inclusion or ranking in them.
Starting soon, as Danny Sullivan at Search Engine Land reports, Google will make ads for certain kinds of products look like search results.
For instance, when you search for "Hotels in San Francisco" today, one of the listings near the top is for a Google property called "Hotel Finder." It's colored yellow — like all ads on Google's search results — and clearly marked "Comparison Ad."
Now, Google is changing the wording to "Sponsored" and getting rid of the yellow background. It's also rearranging the order, so the Hotel Finder appears immediately above organic search results.
Google told Sullivan it gets paid a lead fee (or would like to get paid) whenever you click through to book a result in the Hotel Finder.
Google has similar products with flight information and financial information.
A lot of vertical search engines like Kayak already do this. And Google isn't including paid listings in its main search engine results — at least not yet.
But it's another example of how Google is putting into action its new philosophy that "ads are just more answers," as it stated in its last annual report.