Who are these tracking companies? Meet AddThis.

AddThis is a social bookmarking service that allows website owners to add social media sharing widgets and buttons to their websites (those rows of “share this” buttons you see on lots of websites are actually tracking visitors). They can then track and analyze data around the content shared through these widgets, and provide insights to advertisers. AddThis is on 14 million sites and generates 10 terabytes of data every day.

How it works:

When you visit a website that’s part of the AddThis network, you might notice a column or row of social media sharing icons (Facebook, Twitter, Google+, etc.) next to content like blog posts or articles. If you choose to share content using one of those buttons, AddThis collects data around what you shared, the words you highlight and copy on websites, your clicks, and the kinds of content you and your friends find most interesting. They also build huge social graphs around this data to find similar networks.

For example, let’s pretend you and your friends tend to share articles about cats to Facebook. Let’s also pretend you and your friends happen to be very responsive to ads for a certain type of cat food. AddThis will comb its social graph for sets of friends who also share those same kinds of articles to Facebook, and then show those groups the same cat food advertisements to see if those friends are as responsive as you and yours.

So what?

In AddThis’s words, “What you share and who you share it with can tell you a lot about a person. And when you look at what millions of web users are sharing every day, you can learn an awful lot about your customers.” Users are never informed that AddThis is harvesting their behavioral data, even if they never interact with a “Share this!” widget on any page. AddThis has set a precedent of changing how the massive amounts of data they’re gathering from the pages using their widgets is being used, without informing the publishers of those pages.

On one hand, AddThis has gotten into trouble with the FTC in the past with questionable uses of their technology, like installing cookies that, even when a user manually deleted them, could “revive” themselves within the user’s browser. On the other hand, AddThis is now an active member of two advertising industry organizations that are focused on protecting consumer privacy: the Network Advertising Initiative (NAI) and the Direct Advertising Alliance (DAA). AddThis no longer installs cookies on users’ browsers and the huge social graphs that they build are anonymized…but if they ever shared this data with someone who had even a fraction of your sharing interests affiliated with your real identity, that data can easily create a full picture of your social media activity and interests. This may not be information you want available to others.

How might AddThis benefit me?

AddThis’ goal behind all of the data collection they do around your social media sharing is to serve up more relevant ads based on your interests. They have also made it easier for you to share content from the websites that you like. (It’s worth noting that even when DoNotTrackMe blocks AddThis, you can still share that content just as easily.) Conversely, they’re making it easier for websites to track what kinds of content their readers like you are liking, and that (usually) means more of that same kind of content.

Want to dig even deeper? Check out AddThis’s privacy policy.
Read more about some of the other trackers DNTMe is now blocking:

• AdRoll
• Gravity
• LeadLander
• Dataium
• Meteor Solutions
• [x+1]
• Rapleaf
• KISSmetrics
• BlueKai