Microsoft and Google have been rivals for a long time. In spite of spending billions of dollars, Bing isn't overtaking Google's search engine, and Hotmail email addresses aren't that much cooler, even if they're now branded as Outlook.com and really are much easier to use. Microsoft hired a former Clinton political campaign adviser to handle their new PR campaign, which has aggressively attacked Google with things like blind search comparisons, shopping search, and now a new campaign against Gmail. This new campaign has all the subtlety of a political attack ad. Don't get "Scroogled," it warns, and then implies that Google is breaching your privacy by reading all your Gmail messages to serve ads. Oh no! Is it true?
While technically correct, it's certainly an alarmist claim meant to imply Google doesn't respect your privacy while Microsoft does. It's a complaint that is highly likely to backfire. Let's unpack it.
Google has used automation to serve ads based in part on keywords since Gmail launched in 2004. That isn't a secret and isn't the same as having a person read your individual messages. This isn't any different than the sort of keyword based ads you'll see when you visit individual websites, including this one, and it isn't any different than the sort of contextual ads you'll see if you're using Bing. It's pretty much accepted practice for Internet advertising these days. If it bothers you to see contextual ads next to your email, check your Gmail inside a desktop client. You won't see the ads at all.
Furthermore, if you use Gmail online or mobile and are ever disturbed by an ad you think is inappropriate, you can block individual advertisers through Google Ad Preferences, or you can opt out of getting personalized ads at all. That's right, you can turn the whole thing off. You still see ads, because that's how Google makes money, but they won't be based on your emails or search terms.
Microsoft also shows ads in their Outlook.com email service, but they base their ads on the demographic info you provide when you sign up for the service, so things like your age, geographic location, and gender will end up fueling ad campaigns instead of the keywords you use in an email. Microsoft may also use data from your Xbox, Windows phone, and Internet browsing sessions to serve ads. As with Google, you can opt out of ad personalization.
However, both services "read" your email in the sense that they both have automated systems that scan messages. Trust me. This is a good thing. That's how spam detection works.
So in this case, we have Microsoft attacking Google for doing something that isn't terribly different from what it itself does. Both companies personalize ads based on the user. Both services allow users to turn off the ad personalization. Neither service shares personal information with advertisers. Both services "read" your email before delivering it to your inbox.