Question about the meaning of “tie [something] back to the individual”

Question

Meanwhile Facebook said of the purchase: “The Moves team has built an incredible tool for the millions of people who want to better understand their daily fitness activity, and we're looking forward to the app continuing to gain momentum.”

The app runs in the background of users' phones, using location data to monitor activities through the day.

The free app has been downloaded more than four million times for both iPhone and Android phones, according to the firm.

Many of the big technology firms are seeing money to be made from health technology. There is a range of fitness bands and smartwatches on the market already.

Apple is rumoured to be on the verge of launching its own smartwatch with fitness features and Google last month launched software for wearables.

But for Facebook, the purchase of a fitness app is likely to be all about new data which will allow it to better target adverts, thinks Alys Woodward, an analyst with research firm IDC.

“They want to know more stuff about what people do and where they are. This is useful information even if they don't tie it back to the individual,” she said.
_{Source: BBC News – Facebook buys fitness app firm}

What is the meaning of “tie it back to the individual” in this context? I would appreciate your help if you could determine what the words "it" & "they" refer to when saying " This is useful information even if they don't tie it back to the individual"

Answer 1

Meaning
In this case, the information is valuable to Facebook even if it isn't associated with a specific person. That is to say that they don't need to know the identity of the user to make use of the information.

• “They”
  Woodward was referring to Facebook when she said “they”. The key is the previous sentence, which sets up the quotation from her (“it” in this case also means Facebook):

  But for Facebook, the purchase of a fitness app is likely to be all about new data which will allow it to better target adverts, thinks Alys Woodward, an analyst with research firm IDC.

• “It”
  In “. . .even if they don’t tie it back to the individual”, “it” refers to the information mentioned in the earlier part of the sentence and described in her first sentence:

  They want to know more stuff about what people do and where they are. This is useful information even if they don't tie it back to the individual.

• “Back”
  The idea behind the “back” motion of all this is that the company already knows who these people are, so this kind of data coming from things these people are wearing could be taken in the present or future and matched up with the file each person already has on record.

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How this is different from what they usually do
Much of what Facebook collects is data about individuals, such as the media they consume and activities they like. These preferences, combined with demographic information such as gender and location, allow Facebook to target ads to narrow groups of people and give advertisers more ‘bang for their buck.’

How anonymous data is useful
Monitoring user location and activity throughout the day, could provide a valuable set of data in the aggregate such as traffic patterns, popularity of businesses, etc.

Why it matters whether or not the data is valuable without user identity information
This is key because knowing where someone is and who they are is a breach of privacy, but knowing where a bunch of people are without knowing any of their identities is not.