The big news in the search engine world has been about the tension and accusations between Bing and Google this week. In the past, Google has said that Bing is its main competitor in the online search marketing world, and the two continue to for dominance in paid search marketing

This week’s fight started with a post by Danny Sullivan on Search Engine Land. Apparently Google ran a “sting operation” to prove that Bing was monitoring Google results to improve its own results.  Google posted forced search results to test to see if Bing would pick up the same results, which Bing did. Google claimed that Bing was copying their algorithm and compared it to a student copying off another student’s exam.

Bing responded with an official blog post in which they said:

To be clear, we learn from all of our customers. What we saw in today’s story was a spy-novelesque stunt to generate extreme outliers in tail query ranking. It was a creative tactic by a competitor, and we’ll take it as a back-handed compliment. But it doesn’t accurately portray how we use opt-in customer data as one of many inputs to help improve our user experience.

Google then responded with this blog post, titled “Microsoft’s Bing uses Google search results—and denies it.” The post explains in detail the experiment Google used.

As we see it, this experiment confirms our suspicion that Bing is using some combination of:

• Internet Explorer 8, which can send data to Microsoft via its Suggested Sites feature
• the Bing Toolbar, which can send data via Microsoft’s Customer Experience Improvement Program

or possibly some other means to send data to Bing on what people search for on Google and the Google search results they click. Those results from Google are then more likely to show up on Bing. Put another way, some Bing results increasingly look like an incomplete, stale version of Google results—a cheap imitation.

At Google we strongly believe in innovation and are proud of our search quality. We’ve invested thousands of person-years into developing our search algorithms because we want our users to get the right answer every time they search, and that’s not easy. We look forward to competing with genuinely new search algorithms out there—algorithms built on core innovation, and not on recycled search results from a competitor. So to all the users out there looking for the most authentic, relevant search results, we encourage you to come directly to Google. And to those who have asked what we want out of all this, the answer is simple: we’d like for this practice to stop.

The drama continued with a new post by Bing, called “Setting the Record Straight,” in which Bing denied copying anything from Google.

We do not copy results from any of our competitors. Period. Full stop. We have some of the best minds in the world at work on search quality and relevance, and for a competitor to accuse any one of these people of such activity is just insulting.

Bing even went a step further by accusing Google of “click fraud.”

Google engaged in a “honeypot” attack to trick Bing. In simple terms, Google’s “experiment” was rigged to manipulate Bing search results through a type of attack also known as “click fraud.” That’s right, the same type of attack employed by spammers on the web to trick consumers and produce bogus search results.  What does all this cloak and dagger click fraud prove? Nothing anyone in the industry doesn’t already know. As we have said before and again in this post, we use click stream optionally provided by consumers in an anonymous fashion as one of 1,000 signals to try and determine whether a site might make sense to be in our index.

The battle rages on between Bing and Google with no clear winner.