Last week, Bing launched the Don’t Get Scroogled campaign, bad-mouthing Google Shopping. After being called out in the press for its own practices, Bing is now blasting Google again. This time, it’s about Google’s reaction to the Scroogled campaign.

The Bing Team writes on its blog today, “How did Google respond? They distributed a statement praising their service. They highlighted how great products look on Google Shopping without really explaining how the products get there in the first place. They did not contradict or argue any of the facts and information we laid out. The silence is disappointing given how important this issue is to consumers and the online industry as a whole.”

“In short, Google’s silence is pretty clear acknowledgement of the changes they have made to introduce pay-to-rank to their system,” the team adds.

Bing then takes the opportunity to talks about how it “differs” from Google Shopping:

Unlike Google Shopping, we will not take money to boost a merchant’s rank in our shopping search results. In short, we don’t do pay-to-rank. Where we do have ads, we label them clearly as ads.

While Google has purged Google shopping of each and every free listing, we continue to have well over a hundred million product offers listed for free from merchants across the nation, and new products and offers come in to Bing shopping daily at no cost to merchants who established themselves with us before the holiday season.

As in the past, we are not accepting new merchants during the holiday season, because we want to maintain the integrity of our system for consumers during the holiday rush. But we will re-open the system to new merchants and their free listings in January, as we did last year.

We do take product feeds from 3rd party companies who charge merchants for syndication across internet shopping sites, but the fact that a merchant has paid to be included in that syndicated feed does not affect the position of that merchant’s offer in Bing Shopping’s search results. It’s only a part of the larger set of databases we draw from.

In a post-Scroogled article, veteran search industry blogger Danny Sullivan looks at Bing’s “lack of disclosure”.

“How can consumers know what’s paid and what’s not? If that’s the issue Bing is concerned about, it not only fails to explain this at Bing Shopping but worse suggests that payment isn’t involved, when it is,” Sullivan writes, before drilling into “Bing’s pay-to-play program”. Sullivan spoke with Bing’s Stefan Weitz:

“There’s paid inclusion and there’s pay-to-rank,” Weitz said. “That’s a far different scenario than having to pay Google to be there,” he explained.

The point Weitz’s is trying to make is that with Google, if you don’t pay, you have no chance of ranking at all, because you don’t get included at all. With Bing Shopping, paying is one way of being included, but not the only way, so he doesn’t count that as a ranking factor.

Google, by the way, maintains that it isn’t giving merchants top rankings just because they paid more, which is contrary to the claim by Bing that Google is “selling their shopping results to a high bidder”.

On Monday, Bing re-launched the Bing It On campaign in a special holiday edition.