[zmmmmm]

It's a subtle point, but the whole point of this issue is that Bing actually does copy more than just "clickstream data". Think about what "clickstream" data is - user clicks a link, the link and the text of the link get sent to Microsoft. But in Google's text the search term was not in the link text, nor was it in the target page the user went to. So then how does the search term end up in Bing's index? They have to get it from somewhere - where? The logical conclusion is they get it from the URL of the page the click is performed on, or from the referrer header when the link is clicked (essentially these are the same thing). But how do you do that generically? The search URL contains the query terms in a format that is unique to Google. The only way Bing can be seeing it is if they deliberately are parsing out the Google search terms by specifically targeting how Google encodes them.

So rather than just generically "incorporating clickstream data" this is actually using a special procedure to extract search terms from clicks that are determined to be google searches and then putting those search terms into the bing index.