In the first of many significant changes that Facebook is rolling out to its developer platform, the company introduced a new home page news feed on October 23rd. This new design made the default view of users news feed an algorithmically-tuned “Top Stories” feed, with the live stories feed still available through the click of a button on the home page. The change may now be significantly impacting the growth and engagement numbers of social gaming applications, although the change is so new that this is the first week where we might see meaningful evidence.

Games that have done well in recent weeks continue to lead, although some appear to be seeing their daily active user counts level out despite the growth. Given all the other changes Facebook has planned for the platform in the next few months, watch for potentially big shifts in our weekly lists going forward.

	Name	MAU	Gain	Gain, %
1.	Café World	27,977,880	+4,163,216	+14.88
2.	FarmVille	62,923,096	+1,262,767	+2.01
3.	Death Story	1,055,404	+1,055,388	+100.00
4.	Bejeweled Blitz	10,234,486	+846,585	+8.27
5.	Pet Society	21,521,684	+807,488	+3.75
6.	Restaurant City	18,012,216	+557,768	+3.10
7.	Mobsters 2: Vendetta	3,934,386	+435,068	+11.06
8.	Tattoodle	5,403,633	+337,726	+6.25
9.	Forever Friends	1,416,490	+286,939	+20.26
10.	Pillow Fight	2,554,608	+277,987	+10.88
11.	JibJab	822,223	+263,605	+32.06
12.	Animal Paradise	4,180,206	+233,082	+5.58
13.	(Lil) Farm Life	5,984,443	+216,527	+3.62
14.	Which Zodiac Sign Are You Most Compatible With?	617,788	+203,564	+32.95
15.	Vampire Wars	3,961,179	+203,393	+5.13
16.	Barn Buddy	7,065,975	+202,037	+2.86
17.	Country Story	8,342,134	+201,299	+2.41
18.	Texas HoldEm Poker	18,755,446	+182,255	+0.97
19.	what are you born to do?	806,029	+176,489	+21.90
20.	Sorority Life	7,401,778	+174,246	+2.35

Before we get into the numbers, there are a few reasons why the news feed changes could be impacting apps. Top Stories uses an algorithm to figure out what your friends are doing that will be most interesting to you, which is in essence how the news feed worked before Facebook switched to the live stream in March. Now, Facebook has said, Top Stories is based in part on engagement factors like how often you comment or like other peoples items — although the company has not made all of the details of the algorithm available.

Also, both the new Top Stories feed and the live feed now contain photos, events and other content that formerly appeared in the “Highlights” section on the right-hand side of the old home page. Putting all this content into the feeds means potentially less room for the stories that users share with each other about their actions in apps.

In terms of the user experience, the result for most users is that they see fewer stories about apps than before. So in order for an app to maintain its daily user base, people actually have to want to use it. See this article for more coverage of forthcoming changes.

The fastest-growing game this week is virtual aquarium decorating app Happy Aquarium, made by CrowdStar. The app has had a few big weeks, and this past one it gained 4.40 million users to reach 22.8 million monthly actives. In terms of daily active users, though, the app has stayed relatively flat at around 6 million. Note: The game no longer officially appears in the “games” category, even though it had in past weeks. So that’s why the game is not on the list. It’s not clear why CrowdStar would have made the change — perhaps they didn’t feel that the app was so much of a game? We’re going to keep covering it here, in any case.

DAUs also appear to have flattened for Zynga’s latest hit, Café World. The virtual restaurant game gained 4.16 million to reach 28 million monthly actives. But DAUs have apparently flattened since the redesign went into place, with around 7.76 million as of yesterday. Other leading Zynga titles, like FarmVille and Roller Coaster Kingdom, also appear to be slightly flattening.

Going on down the list, the trend generally seems to be that game DAUs are slightly flattening, although some, like Popcap Game’s Bejeweled Blitz, continue to see DAU growth.

Another way to look at the data is by checking out our top game developer leaderboard on AppData. These top developers show the same trend: Flattening or slight lower DAUs since the 23rd.