Zynga, Other Developers See Big Growth In this Week’s Fastest-Growing Apps by MAU

[Update: Facebook has responded to let us know that the below stats are due to a bug in their reporting, which they’re currently working on fixing.]

Each Monday we run a list of the fastest-growing games on Facebook by monthly active users, and this morning is no exception. However, we’re also seeing some very unusual stats today, starting with a 15 million MAU gain for Zynga’s Café World.

Going down the list, several more games appear to have added huge numbers of users, including Texas HoldEm PokerMafia Wars, Zoo World and Restaurant City. While Zynga is the publisher of many, the gains aren’t limited to that company; Zoo World, for instance, is by RockYou!, while Restaurant City is owned by Electronic Arts.

There are, however, two things that unite most of these games. The first is that they’re months old — meaning growth is typically lower for them than a new game like FrontierVille. Second, all of them appear to have made their huge gains over just the past three days.

We’ll show you a growth chart after the AppData top 20 list:

Top Gainers This Week – Games
Name MAU Gain Gain,%
1. Original Café World 35,324,196 +15,100,354 +75%
2. Original Texas HoldEm Poker 41,597,080 +13,612,033 +49%
3. Original Mafia Wars Game 24,142,623 +6,429,541 +36%
4. Original Zoo World 12,857,340 +6,053,805 +89%
5. Original PetVille 17,823,978 +3,861,130 +28%
6. Original FrontierVille 24,984,631 +3,598,109 +17%
7. Original Restaurant City 13,017,032 +2,289,626 +21%
8. Original Happy Island 8,681,928 +2,044,392 +31%
9. Original Sorority Life 4,978,879 +1,750,713 +54%
10. App_2_125301840827866_9721 Market Street 1,828,168 +1,674,500 +1,090%
11. Original Friends For Sale! 3,377,538 +1,402,706 +71%
12. Original Pirates Ahoy 1,472,230 +916,416 +165%
13. Original Bejeweled Blitz 12,269,911 +854,981 +7%
14. Original 創世紀2012 856,566 +838,705 +4,696%
15. Original 守衛家園 872,822 +836,817 +2,324%
16. Original 德州撲克 2,934,574 +782,991 +36%
17. Original Fashion World 3,642,194 +775,090 +27%
18. Original Baking Life 4,728,301 +640,790 +16%
19. Original Fanglies 1,466,779 +626,714 +75%
20. App_2_142353512445750_6113 Pregunta a Pulpo Paul 957,599 +541,437 +130%

Now here’s the MAU chart for Cafe World; note the hockey stick growth at the end. It looks about the same for each game listed above:

What’s going on? It’s possible that Facebook is just experiencing a temporary bug in its stats reporting. The growth occurred over the weekend, so we haven’t yet had a chance to catch up with the company.

Zynga, also, has not yet responded to let us know whether it has really gained 47 million MAU. However, among two developers we’ve checked with, one said the growth spikes seemed consistent for their apps — and another said, no, the growth did not seem consistent.

The other possibility, besides a bug, is that Facebook has changed or updated its reporting tools. This would not be the first time. The most recent was on June 21st, when Quiz Planet! suddenly reported 15 million new monthly active users, while other apps like Twitter and Facebook for Android also showed big, unexplained gains.

Those June changes turned out to be revealing accurate numbers for apps that had been mis-reporting their stats for months. If that’s the case here, then the social gaming world will need to reconsider its thesis that Zynga, which is by far the largest and most powerful company in the space, is losing large numbers of its users.

Other companies also appeared to gain a few million MAU, but Zynga is the only one showing a monster bump in user numbers. We’ll continue trying to get an official statement this morning.

Just for reference, Zynga’s MAU chart is below; it has risen from 206 million MAU to 253 million MAU. Its highest MAU count ever was also 253 million, in mid-April of this year.