Facebook's (NASDAQ:FB) decision to force its mobile users to download a second app to send messages directly to their contacts has been both a success and a failure. The app stands at No. 1 for free apps in both Apple's App Store and Google's Play Store, but a backlash appears to be building.

Reviews in the two app stores are overwhelmingly negative. Apple breaks out reviews of the latest version of the app -- the one released after the company decided to remove messaging from its core app -- and they are crushingly bad. Viewing the stats for Messenger Version 9.1 on an iPhone shows that as of Monday morning, more than 17,000 reviewers give the app a cumulative score of one star out of five.

Google does not separate reviews for a new version from old ones, so Messenger still comes in with a 4.1 out of five stars, with more than 7 million reviews. But the latest reviews suggest Android users are as upset as those using iOS. The vast majority of recent reviews are for one or two stars, with many expressing anger at being forced to download a second app. 

"It isn't the right move to require all Facebook members [to] 'have' to download an additional app to communicate through messages with Facebook. It was part of the original app and they are just forcing their users to download additional products of theirs when the original worked just fine," wrote Stephen Lestyan in a review that was representative of the sentiments of thousands. 

Scrolling through the thousands of reviews left in August shows that almost nobody had anything positive to say, and many appear very angry. Facebook may have succeeded in making people take the app, but they clearly don't like the way it was done. 

Why is Facebook doing this?
The short answer is that it's better to have people use two of your apps than one. Facebook believes, probably correctly, that if users have a separate Facebook-owned messaging app installed on their phones and tablets, they will send more messages than they do with messaging being part of an already-crowded Facebook app. More messages means more opportunities to sell ads or otherwise monetize though the Messenger app, which is currently ad-free.

In April the company made the following statement:

Today we are starting to notify people that messages are moving out of the Facebook app and over to the Messenger app. To continue sending messages on mobile, people will need to install the Messenger app.

The social media giant attempted to justify the move, saying it would now be able to "focus on making Messenger better for everyone rather than working on two messaging experiences." The company also said the split would improve chat abilities for many users, with Facebook data suggesting replies are 20% faster on Messenger.

Consumers seem to like things the old way, and outrage has been high since the split was announced. That said, outrage is high whenever Facebook makes or announces any sort of change. And history has shown us that has not led people to leaving the social media site, because no clear alternative exists. It's not easy to decamp for another social media site if your friends, family, and contacts aren't there.

Facebook has a near-monopoly, and unlike the cable companies that mostly used their monopolies to slowly raise prices, Facebook is using its to extend its empire.

Can Facebook keep pushing its customers around?
Facebook has so many users that it makes it hard for both competitors and customers. A company can release a better social media product that consumers love, but until it can add a few hundred million daily visitors, it's not really an alternative. This lack of anyplace else to go has allowed Facebook to do things its users don't like.

In some cases, those things actually benefit the product in the long run. It's a huge advantage for Facebook that its size and relative lack of competition allows the company to evolve without caring about public opinion. If Twitter decided to cut post lengths to 100 characters and the public hated it, the company might be forced to reverse its decision because people can just leave. That's theoretically true for Facebook, but leaving means forgoing the things Facebook offers because it has so many users.

Your grandmother and high school soccer coach may not be on other social media platforms. Facebook has the birthdays, life events, and other news from so many users, it's hard for most people to not be there. 

Facebook pushes its users where it thinks they should go for the company's sake and their own -- at least that's how Facebook appears to see it. Until another social media or messaging platform approaches Facebook's user base, it will be able to continue to do so without fear of losing users. It's not impossible to compete with Facebook; WhatsApp was on its way to doing so when Facebook bought it for $19 billion. But until that competition arrives, Facebook can do whatever it wants.