Comment by mavelikara

Here is what the _current_ content says:

  One of the interesting dichotomies with compensation data 
  is that many users want this information, but don’t want to 
  have their individual data exposed or connected back to them.  
  Salary information is personal to each of our members. With 
  this in mind, and consistent with our Members First organizational 
  philosophy, one of the first goals we established when we set out 
  to embark on this project was to provide powerful salary insights 
  in aggregate without risking an individual’s private information. 
  In the end, we built a salary collection system to provide the 
  strongest protections for the anonymity of all of our members—no 
  easy task. Parts of our approach are detailed later in this article.

  Because we proactively separate a member’s submission data from their 
  Member ID when compensation data is submitted, it enables us to 
  secure the system in such a way that we cannot even support the 
  ability for a member to update their previously submitted salary 
  information - they have to resubmit. Furthermore, our system provides 
  protection not just from hackers out in the wild, but also provides 
  access control against unauthorized use by internal users.
  

If I am reading this correctly, what they seem to say is that as implemented currently, they don't have the ability to track a person's salary information to their profile and hence won't be able to sell that information.