Recently Australian online shopping portal Kogan.com started imposing an extra 6.8% tax on users who are using Internet Explorer 7 or below to make their purchases. Termed the "Internet Explorer Tax", kogan.com hoped that this will force users to upgrade from the outdated browser and was applauded by many.

Today there is a new twist as Kogan.com has disappeared from the Microsoft owned Bing search results. Here is the Bing result for the search term "kogan.com".

A search for the same term in Google shows kogan.com as the top result.

Microsoft obviously has some explaining to do. However, it seems unlikely that Microsoft had deliberately removed kogan.com from its search results for two reasons.

First of all, Microsoft themselves wants people to upgrade their browser. They have a website www.ie6countdown.com where they are urging people to upgrade their browser. When Microsoft themselves so openly want people to upgrade, it seems unlikely that they will resort to such an extreme reaction to kogan.com's "tax".

The second reason is that Microsoft is trying to make a mark against Google with its search engine, Bing. They would be very well aware that removing kogan.com from the search results will blow up in their face and irreversibly damage the reputation and trust of their search engine.

So, what is going on then? We will not know until Microsoft releases a statement. There is an interesting discussion going on in Hacker News about this with some possible explanations.

I reckon this is because the ranking algorithm deranked them when their click through from bing rate declined after the sudden publicity storm. Their #visitors delta probably went very negative after everyone stopped clicking links from various news sites. - gouranga

Maybe the storm of incoming links about the IE7 news accidentally got identified as linkfarming somehow? - AshleysBrains

Update:

Looks like this is not a case of a glitch in Bing's ranking algorithm. A search for site:kogan.com yields no results which means that all kogan.com pages have been removed from Bing's index.