I certainly don’t know why Microsoft thought it was the public’s desire to be tracked by advertisers by default in the first place. You might not know it but by default IE does allow this. It might surprise you to know the new IE10 will be the first of the major browser to NOT do this by default.
Advertisers track your browser via session data. The information sought by advertisers is easily blocked. Google Chrome (policy), Firefox and Internet Explorer have had the option to block your information from ad trackers for years. They all opted to force you to know about it and shut it off yourself.
Microsoft hasn’t been the pioneer in the area of end user privacy in past. They usually are the first to bow to market insistance to open up more user data. It’s an interesting move. Google’s email platform hurt Microsoft. They didn’t really seem to see cloud based email solutions as a threat to mid-sized corporate mail solutions. As time has gone by, it’s clear people are willing to sacifice control and security for a free mail solution.
What surprised most people was that Google’s free solution quickly became a choice. Pay more than it was costing you before you moved (in most cases) or have our software read your email and toss advertisements at you in relation to the content in your email. I’ve heard most people describe the advertising approach as “creepy”. It would seem that Microsoft is positioning themselves on being the less “creepy” choice. Although I personally think as more attacks and breaches occur there will be a lot of businesses descending from clouds to return to the realtive safety of security though obscurity.
You can find this setting within your privacy settings in the IE Options on older versions.