Node/Express not saving updated company information to DB

I'm very new to Node/Express, and trying to implement this block that updates a company's information. I have a number of console.log statements that are tracking the variables throughout the block, and everything seems to be working perfectly fine until the last saving line. What exactly could I be doing wrong?

// Edit company metric information
  editMetrics: function(link, form, cb) {
    Companies.findOne({ permalink: link }, function (err, company) {
      if (err)  return done(err);

      // Iterate through form fields
      for(var field in form) {
        console.log(field);  // Looks great

        if(typeof(company.operational[field]) !== 'undefined') {
          company.operational[field].unshift({
            timestamp: new Date(),
            value: form[field]
          });
        }

        if(typeof(company.user_metrics[field]) !== 'undefined') {
          company.user_metrics[field].unshift({
            timestamp: new Date(),
            value: form[field]
          });
        }

        if(typeof(company.economics[field]) !== 'undefined') {
          company.economics[field].unshift({
            timestamp: new Date(),
            value: form[field]
          }); 
        }      
      }

      console.log(company); // Looks great

      // Save & redirect to updated profile
      company.save(cb());  // For some reason this isn't saving
    });
  },

Callback:

CompanyModel.editMetrics(link, req.body, cb = function(error, result) { 
    res.redirect('/portfolio/' + link); 
  });