Javascript recursion (recursive function) with promises

gistfile1.js

var getAll = function(url, page, acquired, deferred) {
  var self = this;
  page = page || 1;
  deferred = deferred || $q.defer();
  var page_url = [url, '&page=', page].join("");
  $http.get(page_url).then(function(results) {
    acquired = acquired ? acquired.concat(results.data) : results.data;
    if (results.data.length === 100) { // Assuming the max is 100 per page...
      return self.getAll(url, ++page, acquired, deferred);
    } else {
      deferred.resolve(acquired);
    }
  });
  return deferred.promise;
}