diff --git a/browser/modules/DirectoryLinksProvider.jsm b/browser/modules/DirectoryLinksProvider.jsm
index c61688a28518..1c1595e2f397 100644
--- a/browser/modules/DirectoryLinksProvider.jsm
+++ b/browser/modules/DirectoryLinksProvider.jsm
@@ -15,6 +15,7 @@ const XMLHttpRequest =
 Cu.import("resource://gre/modules/XPCOMUtils.jsm");
 Cu.import("resource://gre/modules/Services.jsm");
 Cu.import("resource://gre/modules/Task.jsm");
+Cu.import("resource://gre/modules/Timer.jsm");
 
 XPCOMUtils.defineLazyModuleGetter(this, "NetUtil",
   "resource://gre/modules/NetUtil.jsm");
@@ -89,6 +90,11 @@ let DirectoryLinksProvider = {
    */
   _relatedLinks: new Map(),
 
+  /**
+   * A set of top sites that we can provide related links for
+   */
+  _topSitesWithRelatedLinks: new Set(),
+
   get _observedPrefs() Object.freeze({
     enhanced: PREF_NEWTAB_ENHANCED,
     linksURL: PREF_DIRECTORY_SOURCE,
@@ -432,7 +438,10 @@ let DirectoryLinksProvider = {
     }).catch(ex => {
       Cu.reportError(ex);
       return [];
-    }).then(aCallback);
+    }).then(links => {
+      aCallback(links);
+      this._populatePlacesLinks();
+    });
   },
 
   init: function DirectoryLinksProvider_init() {
@@ -441,6 +450,9 @@ let DirectoryLinksProvider = {
     // setup directory file path and last download timestamp
     this._directoryFilePath = OS.Path.join(OS.Constants.Path.localProfileDir, DIRECTORY_LINKS_FILE);
     this._lastDownloadMS = 0;
+
+    NewTabUtils.placesProvider.addObserver(this);
+
     return Task.spawn(function() {
       // get the last modified time of the links file if it exists
       let doesFileExists = yield OS.File.exists(this._directoryFilePath);
@@ -453,6 +465,47 @@ let DirectoryLinksProvider = {
     }.bind(this));
   },
 
+  _handleManyLinksChanged: function() {
+    this._topSitesWithRelatedLinks.clear();
+    this._relatedLinks.forEach((relatedLinks, site) => {
+      if (NewTabUtils.isTopPlacesSite(site)) {
+        this._topSitesWithRelatedLinks.add(site);
+      }
+    });
+  },
+
+  _handleLinkChanged: function(aLink) {
+    let changedLinkSite = NewTabUtils.extractSite(aLink.url);
+    if (!NewTabUtils.isTopPlacesSite(changedLinkSite)) {
+      this._topSitesWithRelatedLinks.delete(changedLinkSite);
+      return;
+    }
+
+    if (this._relatedLinks.has(changedLinkSite)) {
+      this._topSitesWithRelatedLinks.add(changedLinkSite);
+    }
+  },
+
+  _populatePlacesLinks: function () {
+    NewTabUtils.links.populateProviderCache(NewTabUtils.placesProvider, () => {
+      this._handleManyLinksChanged();
+    });
+  },
+
+  onLinkChanged: function (aProvider, aLink) {
+    // Make sure NewTabUtils.links handles the notification first.
+    setTimeout(() => {
+      this._handleLinkChanged(aLink);
+    }, 0);
+  },
+
+  onManyLinksChanged: function () {
+    // Make sure NewTabUtils.links handles the notification first.
+    setTimeout(() => {
+      this._handleManyLinksChanged();
+    }, 0);
+  },
+
   /**
    * Return the object to its pre-init state
    */
diff --git a/browser/modules/test/xpcshell/test_DirectoryLinksProvider.js b/browser/modules/test/xpcshell/test_DirectoryLinksProvider.js
index 0ba8c96540ca..5255ee618470 100644
--- a/browser/modules/test/xpcshell/test_DirectoryLinksProvider.js
+++ b/browser/modules/test/xpcshell/test_DirectoryLinksProvider.js
@@ -19,6 +19,8 @@ Cu.import("resource://gre/modules/XPCOMUtils.jsm");
 
 XPCOMUtils.defineLazyModuleGetter(this, "NetUtil",
   "resource://gre/modules/NetUtil.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "NewTabUtils",
+  "resource://gre/modules/NewTabUtils.jsm");
 
 do_get_profile();
 
@@ -58,6 +60,42 @@ const BinaryInputStream = CC("@mozilla.org/binaryinputstream;1",
                               "setInputStream");
 
 let gLastRequestPath;
+
+let relatedTile1 = {
+  url: "http://turbotax.com",
+  type: "related",
+  lastVisitDate: 4,
+  related: [
+    "taxact.com",
+    "hrblock.com",
+    "1040.com",
+    "taxslayer.com"
+  ]
+};
+let relatedTile2 = {
+  url: "http://irs.gov",
+  type: "related",
+  lastVisitDate: 3,
+  related: [
+    "taxact.com",
+    "hrblock.com",
+    "freetaxusa.com",
+    "taxslayer.com"
+  ]
+};
+let relatedTile3 = {
+  url: "http://hrblock.com",
+  type: "related",
+  lastVisitDate: 2,
+  related: [
+    "taxact.com",
+    "freetaxusa.com",
+    "1040.com",
+    "taxslayer.com"
+  ]
+};
+let someOtherSite = {url: "http://someothersite.com", title: "Not_A_Related_Site"};
+
 function getHttpHandler(path) {
   let code = 200;
   let body = JSON.stringify(kHttpHandlerData[path]);
@@ -161,6 +199,7 @@ function run_test() {
   server.registerPrefixHandler(kExamplePath, getHttpHandler(kExamplePath));
   server.registerPrefixHandler(kFailPath, getHttpHandler(kFailPath));
   server.start(kDefaultServerPort);
+  NewTabUtils.init();
 
   run_next_test();
 
@@ -176,40 +215,6 @@ function run_test() {
 }
 
 add_task(function test_relatedLinksMap() {
-  let relatedTile1 = {
-    url: "http://turbotax.com",
-    type: "related",
-    lastVisitDate: 4,
-    related: [
-      "taxact.com",
-      "hrblock.com",
-      "1040.com",
-      "taxslayer.com"
-    ]
-  };
-  let relatedTile2 = {
-    url: "http://irs.gov",
-    type: "related",
-    lastVisitDate: 3,
-    related: [
-      "taxact.com",
-      "hrblock.com",
-      "freetaxusa.com",
-      "taxslayer.com"
-    ]
-  };
-  let relatedTile3 = {
-    url: "http://hrblock.com",
-    type: "related",
-    lastVisitDate: 2,
-    related: [
-      "taxact.com",
-      "freetaxusa.com",
-      "1040.com",
-      "taxslayer.com"
-    ]
-  };
-  let someOtherSite = {url: "http://someothersite.com", title: "Not_A_Related_Site"};
   let data = {"en-US": [relatedTile1, relatedTile2, relatedTile3, someOtherSite]};
   let dataURI = 'data:application/json,' + JSON.stringify(data);
 
@@ -240,6 +245,51 @@ add_task(function test_relatedLinksMap() {
   yield promiseCleanDirectoryLinksProvider();
 });
 
+add_task(function test_topSitesWithRelatedLinks() {
+  let topSites = ["site0.com", "1040.com", "site2.com", "hrblock.com", "site4.com", "freetaxusa.com", "site6.com"];
+  let origIsTopPlacesSite = NewTabUtils.isTopPlacesSite;
+  NewTabUtils.isTopPlacesSite = function(site) {
+    return topSites.indexOf(site) >= 0;
+  }
+
+  // We start off with no top sites with related links.
+  do_check_eq(DirectoryLinksProvider._topSitesWithRelatedLinks.size, 0);
+
+  let data = {"en-US": [relatedTile1, relatedTile2, relatedTile3, someOtherSite]};
+  let dataURI = 'data:application/json,' + JSON.stringify(data);
+
+  yield promiseSetupDirectoryLinksProvider({linksURL: dataURI});
+  let links = yield fetchData();
+
+  // Check we've populated related links as expected.
+  do_check_eq(DirectoryLinksProvider._relatedLinks.size, 5);
+
+  // When many sites change, we update _topSitesWithRelatedLinks as expected.
+  let expectedTopSitesWithRelatedLinks = ["hrblock.com", "1040.com", "freetaxusa.com"];
+  DirectoryLinksProvider._handleManyLinksChanged();
+  isIdentical([...DirectoryLinksProvider._topSitesWithRelatedLinks], expectedTopSitesWithRelatedLinks);
+
+  // Removing site6.com as a topsite has no impact on _topSitesWithRelatedLinks.
+  let popped = topSites.pop();
+  DirectoryLinksProvider._handleLinkChanged({url: "http://" + popped});
+  isIdentical([...DirectoryLinksProvider._topSitesWithRelatedLinks], expectedTopSitesWithRelatedLinks);
+
+  // Removing freetaxusa.com as a topsite will remove it from _topSitesWithRelatedLinks.
+  popped = topSites.pop();
+  expectedTopSitesWithRelatedLinks.pop();
+  DirectoryLinksProvider._handleLinkChanged({url: "http://" + popped});
+  isIdentical([...DirectoryLinksProvider._topSitesWithRelatedLinks], expectedTopSitesWithRelatedLinks);
+
+  // Re-adding freetaxusa.com as a topsite will add it to _topSitesWithRelatedLinks.
+  topSites.push(popped);
+  expectedTopSitesWithRelatedLinks.push(popped);
+  DirectoryLinksProvider._handleLinkChanged({url: "http://" + popped});
+  isIdentical([...DirectoryLinksProvider._topSitesWithRelatedLinks], expectedTopSitesWithRelatedLinks);
+
+  // Cleanup.
+  NewTabUtils.isTopPlacesSite = origIsTopPlacesSite;
+});
+
 add_task(function test_reportSitesAction() {
   yield DirectoryLinksProvider.init();
   let deferred, expectedPath, expectedPost;
diff --git a/toolkit/modules/NewTabUtils.jsm b/toolkit/modules/NewTabUtils.jsm
index 01284234af45..fc5c11c11c72 100644
--- a/toolkit/modules/NewTabUtils.jsm
+++ b/toolkit/modules/NewTabUtils.jsm
@@ -12,6 +12,7 @@ const Cu = Components.utils;
 
 Cu.import("resource://gre/modules/Services.jsm");
 Cu.import("resource://gre/modules/XPCOMUtils.jsm");
+Cu.import("resource://gre/modules/Task.jsm");
 
 XPCOMUtils.defineLazyModuleGetter(this, "PlacesUtils",
   "resource://gre/modules/PlacesUtils.jsm");
@@ -714,18 +715,13 @@ let Links = {
    */
   maxNumLinks: LINKS_GET_LINKS_LIMIT,
 
-  /**
-   * The link providers.
-   */
-  _providers: new Set(),
-
   /**
    * A mapping from each provider to an object { sortedLinks, siteMap, linkMap }.
    * sortedLinks is the cached, sorted array of links for the provider.
    * siteMap is a mapping from base domains to URL count associated with the domain.
    * linkMap is a Map from link URLs to link objects.
    */
-  _providerLinks: new Map(),
+  _providers: new Map(),
 
   /**
    * The properties of link objects used to sort them.
@@ -746,7 +742,7 @@ let Links = {
    * @param aProvider The link provider.
    */
   addProvider: function Links_addProvider(aProvider) {
-    this._providers.add(aProvider);
+    this._providers.set(aProvider, null);
     aProvider.addObserver(this);
   },
 
@@ -757,7 +753,6 @@ let Links = {
   removeProvider: function Links_removeProvider(aProvider) {
     if (!this._providers.delete(aProvider))
       throw new Error("Unknown provider");
-    this._providerLinks.delete(aProvider);
   },
 
   /**
@@ -790,7 +785,7 @@ let Links = {
     }
 
     let numProvidersRemaining = this._providers.size;
-    for (let provider of this._providers) {
+    for (let [provider, links] of this._providers) {
       this._populateProviderCache(provider, () => {
         if (--numProvidersRemaining == 0)
           executeCallbacks();
@@ -840,7 +835,9 @@ let Links = {
    * Resets the links cache.
    */
   resetCache: function Links_resetCache() {
-    this._providerLinks.clear();
+    for (let provider of this._providers.keys()) {
+      this._providers.set(provider, null);
+    }
   },
 
   /**
@@ -878,6 +875,14 @@ let Links = {
     }
   },
 
+  populateProviderCache: function(provider, callback) {
+    if (!this._providers.has(provider)) {
+      throw new Error("Can only populate provider cache for existing provider.");
+    }
+
+    return this._populateProviderCache(provider, callback, false);
+  },
+
   /**
    * Calls getLinks on the given provider and populates our cache for it.
    * @param aProvider The provider whose cache will be populated.
@@ -885,28 +890,42 @@ let Links = {
    * @param aForce When true, populates the provider's cache even when it's
    *               already filled.
    */
-  _populateProviderCache: function Links_populateProviderCache(aProvider, aCallback, aForce) {
-    if (this._providerLinks.has(aProvider) && !aForce) {
-      aCallback();
-    } else {
-      aProvider.getLinks(links => {
-        // Filter out null and undefined links so we don't have to deal with
-        // them in getLinks when merging links from providers.
-        links = links.filter((link) => !!link);
-        this._providerLinks.set(aProvider, {
-          sortedLinks: links,
-          siteMap: links.reduce((map, link) => {
+  _populateProviderCache: function (aProvider, aCallback, aForce) {
+    let cache = this._providers.get(aProvider);
+    let createCache = !cache;
+    if (createCache) {
+      cache = {
+        // Start with a resolved promise.
+        populatePromise: new Promise(resolve => resolve()),
+      };
+      this._providers.set(aProvider, cache);
+    }
+    // Chain the populatePromise so that calls are effectively queued.
+    cache.populatePromise = cache.populatePromise.then(() => {
+      return new Promise(resolve => {
+        if (!createCache && !aForce) {
+          aCallback();
+          resolve();
+          return;
+        }
+        aProvider.getLinks(links => {
+          // Filter out null and undefined links so we don't have to deal with
+          // them in getLinks when merging links from providers.
+          links = links.filter((link) => !!link);
+          cache.sortedLinks = links;
+          cache.siteMap = links.reduce((map, link) => {
             this._incrementSiteMap(map, link);
             return map;
-          }, new Map()),
-          linkMap: links.reduce((map, link) => {
+          }, new Map());
+          cache.linkMap = links.reduce((map, link) => {
             map.set(link.url, link);
             return map;
-          }, new Map()),
+          }, new Map());
+          aCallback();
+          resolve();
         });
-        aCallback();
       });
-    }
+    });
   },
 
   /**
@@ -916,8 +935,10 @@ let Links = {
   _getMergedProviderLinks: function Links__getMergedProviderLinks() {
     // Build a list containing a copy of each provider's sortedLinks list.
     let linkLists = [];
-    for (let links of this._providerLinks.values()) {
-      linkLists.push(links.sortedLinks.slice());
+    for (let links of this._providers.values()) {
+      if (links) {
+        linkLists.push(links.sortedLinks.slice());
+      }
     }
 
     function getNextLink() {
@@ -951,7 +972,7 @@ let Links = {
     if (!("url" in aLink))
       throw new Error("Changed links must have a url property");
 
-    let links = this._providerLinks.get(aProvider);
+    let links = this._providers.get(aProvider);
     if (!links)
       // This is not an error, it just means that between the time the provider
       // was added and the future time we call getLinks on it, it notified us of
@@ -1210,7 +1231,7 @@ this.NewTabUtils = {
   },
 
   isTopSiteGivenProvider: function(aSite, aProvider) {
-    return Links._providerLinks.get(aProvider).siteMap.has(aSite);
+    return Links._providers.get(aProvider).siteMap.has(aSite);
   },
 
   isTopPlacesSite: function(aSite) {
@@ -1248,5 +1269,6 @@ this.NewTabUtils = {
   linkChecker: LinkChecker,
   pinnedLinks: PinnedLinks,
   blockedLinks: BlockedLinks,
-  gridPrefs: GridPrefs
+  gridPrefs: GridPrefs,
+  placesProvider: PlacesProvider
 };
diff --git a/toolkit/modules/tests/xpcshell/test_NewTabUtils.js b/toolkit/modules/tests/xpcshell/test_NewTabUtils.js
index e9bed568acff..cf26b1993f67 100644
--- a/toolkit/modules/tests/xpcshell/test_NewTabUtils.js
+++ b/toolkit/modules/tests/xpcshell/test_NewTabUtils.js
@@ -6,11 +6,36 @@
 const { classes: Cc, interfaces: Ci, results: Cr, utils: Cu } = Components;
 Cu.import("resource://gre/modules/NewTabUtils.jsm");
 Cu.import("resource://gre/modules/Promise.jsm");
+Cu.import("resource://gre/modules/Task.jsm");
 
 function run_test() {
   run_next_test();
 }
 
+add_task(function populatePromise() {
+  let count = 0;
+  let expectedLinks = makeLinks(0, 10, 2);
+
+  let getLinksFcn = Task.async(function* (callback) {
+    //Should not be calling getLinksFcn twice
+    count++;
+    do_check_eq(count, 1);
+    yield Promise.resolve();
+    callback(expectedLinks);
+  });
+
+  let provider = new TestProvider(getLinksFcn);
+
+  NewTabUtils.initWithoutProviders();
+  NewTabUtils.links.addProvider(provider);
+
+  NewTabUtils.links.populateProviderCache(provider, () => {});
+  NewTabUtils.links.populateProviderCache(provider, () => {
+    do_check_links(NewTabUtils.links.getLinks(), expectedLinks);
+    NewTabUtils.links.removeProvider(provider);
+  });
+});
+
 add_task(function isTopSiteGivenProvider() {
   let expectedLinks = makeLinks(0, 10, 2);
 
@@ -22,7 +47,7 @@ add_task(function isTopSiteGivenProvider() {
 
   NewTabUtils.initWithoutProviders();
   NewTabUtils.links.addProvider(provider);
-  NewTabUtils.links.populateCache(function () {}, false);
+  yield new Promise(resolve => NewTabUtils.links.populateCache(resolve));
 
   do_check_eq(NewTabUtils.isTopSiteGivenProvider("example2.com", provider), true);
   do_check_eq(NewTabUtils.isTopSiteGivenProvider("example1.com", provider), false);
@@ -62,8 +87,7 @@ add_task(function multipleProviders() {
   NewTabUtils.links.addProvider(evenProvider);
   NewTabUtils.links.addProvider(oddProvider);
 
-  // This is sync since the providers' getLinks are sync.
-  NewTabUtils.links.populateCache(function () {}, false);
+  yield new Promise(resolve => NewTabUtils.links.populateCache(resolve));
 
   let links = NewTabUtils.links.getLinks();
   let expectedLinks = makeLinks(NewTabUtils.links.maxNumLinks,
@@ -83,8 +107,7 @@ add_task(function changeLinks() {
   NewTabUtils.initWithoutProviders();
   NewTabUtils.links.addProvider(provider);
 
-  // This is sync since the provider's getLinks is sync.
-  NewTabUtils.links.populateCache(function () {}, false);
+  yield new Promise(resolve => NewTabUtils.links.populateCache(resolve));
 
   do_check_links(NewTabUtils.links.getLinks(), expectedLinks);
 
@@ -124,8 +147,12 @@ add_task(function changeLinks() {
   // Notify of many links changed.
   expectedLinks = makeLinks(0, 3, 1);
   provider.notifyManyLinksChanged();
-  // NewTabUtils.links will now repopulate its cache, which is sync since
-  // the provider's getLinks is sync.
+
+  // Since _populateProviderCache() is async, we must wait until the provider's
+  // populate promise has been resolved.
+  yield NewTabUtils.links._providers.get(provider).populatePromise;
+
+  // NewTabUtils.links will now repopulate its cache
   do_check_links(NewTabUtils.links.getLinks(), expectedLinks);
 
   NewTabUtils.links.removeProvider(provider);
@@ -138,15 +165,14 @@ add_task(function oneProviderAlreadyCached() {
   NewTabUtils.initWithoutProviders();
   NewTabUtils.links.addProvider(provider1);
 
-  // This is sync since the provider's getLinks is sync.
-  NewTabUtils.links.populateCache(function () {}, false);
+  yield new Promise(resolve => NewTabUtils.links.populateCache(resolve));
   do_check_links(NewTabUtils.links.getLinks(), links1);
 
   let links2 = makeLinks(10, 20, 1);
   let provider2 = new TestProvider(done => done(links2));
   NewTabUtils.links.addProvider(provider2);
 
-  NewTabUtils.links.populateCache(function () {}, false);
+  yield new Promise(resolve => NewTabUtils.links.populateCache(resolve));
   do_check_links(NewTabUtils.links.getLinks(), links2.concat(links1));
 
   NewTabUtils.links.removeProvider(provider1);
@@ -162,8 +188,7 @@ add_task(function newLowRankedLink() {
   NewTabUtils.initWithoutProviders();
   NewTabUtils.links.addProvider(provider);
 
-  // This is sync since the provider's getLinks is sync.
-  NewTabUtils.links.populateCache(function () {}, false);
+  yield new Promise(resolve => NewTabUtils.links.populateCache(resolve));
   do_check_links(NewTabUtils.links.getLinks(), links);
 
   // Notify of a new link that's low-ranked enough not to make the list.