In its first foray with Datalogix, that company that uses rewards card data to make advertising more effective, the social network has found that fewer than 1 percent of in-store sales could be tied to brand advertising campaigns on Facebook, reports Reuters's Alexei Oreskovic. Basically, just because someone clicked on an ad, that doesn't mean that they went into the retailer and bought that thing. Meaning what exactly for you? At least right now: Instead of focusing on getting more people to click, the social network will focus on an ad's frequency. Oreskovic explains: "Instead of one Facebook user seeing an ad 100 times and another user seeing the ad only twice, for example, Facebook says it will soon offer advertisers' insight on the ideal number of ad impressions for a particular campaign," he writes. But, how will it do that? Your data. And that sounds like the new norm for the social network, which will will continue to personalize its branding experience, with what it has called in a separate post a more "relevant ads that protect your privacy.

But how much does it protect privacy, really? When we looked at this Datalogix set-up last week, we mentioned that Facebook would now have access to offline user buying habits, which it didn't have before. And that it would use those drug store purchases to figure out who to target when. In that latest post post Facebook explains its attempts not to overstep its bounds:

Because of our commitment to privacy, we had an industry-leading auditing firm evaluate the privacy implications of this process. The auditor confirmed that, throughout this process, Datalogix is not allowed to learn more about you from Facebook profile information. Similarly, Datalogix does not send us any of their purchase data, meaning we cannot specifically tell whether or not you purchased a marketer’s product. Finally, with this partnership, Datalogix only sends the marketer aggregate information about large groups of people. None of this data is attributable to an individual Facebook user.

CVS, which we mentioned as a possible partner with Datalogix, has defended the practice, too, telling Talking Points Memo's Carl Franzen, "we do not share any personal information without our customers’ permission." That does not quite exempt them from this deal, however. And, even if it is all anonymous via hashing, with the best intentions, it still might make users uncomfortable because of unintended consequences, as privacy expert Ryan Calo explained to The Atlantic Wire last week

Right up top, Facebook gives its main reason for doing any of this in the first place: To keep its site free, reminding us that this is what we get for using the Internet. "Many sites across the web provide free services by including advertisements. Facebook is no exception," writes privacy engineer Joey Tyson. The difference between Facebook and the rest of the "many sites across the web," however is that the ads will know more about you and not just "people like you."