Sometimes it seems that Google has so many different experiments going on with hotel ads and pricing that it is simply planting them in various search results and pages to see which ones sprout.
For example, a Google search for "Chicago hotels" produces an organic result for Omni Chicago Hotel with an ad at the bottom which says, "15% Off Weekends."
When you click on the ad, you find a Google Offer coupon for 15% off on a two-night weekend stay at the property, although Google does not guarantee the legitimacy of the third-party Offer.
Another wrinkle in Google hotel advertising is the Book Now feature on Place pages.
So, if you search for "Orlando hotels" and click on the Place link for the Sheraton Orlando Downtown Hotel, you can select dates for your stay, click on the $129 link and view ads from Priceline, Booking.com, Hotels.com and Expedia.com. There's also a link to the hotel website.
And you can view the variations in pricing among the competitors -- even among affiliated online travel agencies.
So, for example, Priceline offers a king bed at the property for a $129 base rate (or $145 including taxes and fees) while its sister company Booking.com displays a standard room at $139 per night (or $156 with taxes and fees).
Expedia and sister site Hotels.com offer traditional rooms at comparable rates to Booking.com's while the hotel website's rate for the room with the king bed is the same as Priceline's.
Google's Book Now ads show dynamic pricing as the user can change the dates and conduct various searches.
Meanwhile, Search Engine Land uncovered a variety of new Google Hotel Price Ad formats, including local 7-packs with pricing, ads in Google Places and "ads on a local inbox result for a single hotel."
Google spokesman Jim Prosser emphasizes that ads for hotel prices don't skew organic rankings for the properties in Google Maps or elsewhere in Google.
"This is an experiment," Prosser says of the various ad formats. "We're always experimenting with the look and feel of our search results pages, including the delivery of relevant advertising."
Prosser says Google has nothing further to say about its plans for hotel advertising at this juncture.