Facebook is constantly making changes. Users know this, and are often irritated.

Do you think Facebook changes have made it less valuable as a channel for getting apps, content, and messages to go viral? Let us know in the comments.

It seems odd to think about Facebook keeping things from going viral when you consider that historically, it has been such a major force for doing exactly that. Pair that fact with its 800 million users, connected to their friends and family as well as various apps and brand pages, and it almost seems crazy to think that Facebook isn’t the perfect viral channel, and to be clear, nobody’s saying that it can’t still be that with the right approach.

However, things aren’t getting easier in terms of getting things to go viral on Facebook.

Look at Zynga, which makes the most popular games on Facebook. When the company released its latest earnings report, it was revealed that its user base has not been growing significantly, and that its number of daily active users had actually declined year-over-year.

If the company behind Cityville, Farmville, Mafia Wars and Words with Friends (to name a few) is having issues with active users, what does that mean for the smaller guys?

We don’t know the all of the details about why Zynga’s numbers have slumped, but it’s certainly worth noting that a powerhouse like that even seems to be having a bit of trouble. There’s an interesting Quora thread about this.

It’s going to be interesting to see how the Timeline affects the vitalness of messages and apps once its rolled out to everyone. Developers have had access to it since it launched. There might be some interesting ways to use all of these verbs Facebook has added into the new Open Graph mix, but the Timeline has already shown signs of reducing impressions by the way it combines things. For example, you might see something like “20 actions from such-and-such app”, as opposed to separate actions.

Another subtle example would be the way Facebook has recently changed the wording of app notifications. For some apps, you might have seen the app name in the notification message, whereas now, you’d just see “John Doe” posted on your timeline’

Perhaps the biggest blow to Facebook’s viralness value is the recent change to the news feed. Now, obviously not everyone sees the same things in their news feeds. People have different friends and follow different pages, but even among those two users have in common, they may not see the same updates appear in their news feed. Facebook has used its “EdgeRank” algorithm to show people the stuff it deems most relevant to them for quite a while. They recently introduced “Graphrank” for apps to go along with that. The fact that different people using your apps might not see the same updates is something of an obstacle in and of itself, but now there is perhaps more uncertainty than ever as to who is going to see what in their news feed.

Colin Murphy, Director of Social at Skinny, thinks brands got the short end of the stick on the recent news feed changes. “Brands were undervalued in this update in three primary ways,” he says. “First, Facebook Pages weren’t included in the photo display and Recent Stories updates. With Recent Stories, it seems like Facebook’s algorithm will favor a ‘friendship’ over a ‘brand relationship’, meaning brand content won’t show up at the top of a user’s feed. Second, with the updated newsfeed, photos on brand pages won’t look as sleek and big as they do for personal accounts.”

“Third, and possibly most important, when a user ‘likes’ content (again, content, not pages) within the Facebook platform, that content will no longer post to the user’s wall, meaning greatly decreased impressions for brand,” he adds. “To clarify, content outside Facebook that is ‘liked’ will post to that user’s wall.”

Now, one could argue that Facebook’s “ticker” feature, which was introduced alongside these changes counters any lack of viral value presented by the changes to the news feed. The ticker shows you everything your friends do on Facebook, and if you’re Spotify or another launch partner of Facebook’s there’s certainly plenty of viralness there (there were even lots of complaints about users getting spammed by the songs their friends are listening to).

But one has to wonder how much the average Facebook user is truly consuming the content that appears in the ticker. I don’t have any hard numbers on this, but my gut is telling me that a lot of users are all but ignoring it (even if a lot aren’t. remember: 800 million users), in favor of the news feed that they’ve grown quite attached to over the years. Hell, the Facebook mobile apps (even the new iPhone app) doesn’t even have the ticker.

Speaking for myself, I use it some, but I certainly don’t scroll through to see every single update, and there are plenty of users with more friends than me, and their tickers must be overflowing with content (or noise).

We’ve even had readers tell us that they’ve just seen likes from friends on their status updates drop.

What about you? Have you seen less liking or interaction with your apps, updates, etc. as a result of recent Facebook changes? And those could be any changes, even if they weren’t mentioned in the article. Let us know in the comments.