Remember when Facebook introduced the News Feed and people lost their mind? Well, buckle up for Round 2: Facebook announced a major redesign of its mobile app and desktop interface at its F8 developer conference on Tuesday, and there are some significant changes coming.

Facebook's newest iteration will downplay the News Feed in favor of Groups and Events, which are apparently Facebook's two fastest-growing features. Clearly, the company wants to double down on the ways that people are already using its software. After all, Facebook lives and dies by engagement of the community of users it has built.

The redesign also highlights Facebook's attempts to make good on Mark Zuckerberg's promise to increase privacy, by highlighting more personal interaction through private messaging and groups. Instead of mindless scrolling through volumes of publicly shared posts, this likely marks a real transition to a focus on personal communication with the people you actually interact with.

Maybe you're yawning: It's just another redesign. No big deal, right? Wrong. This one matters. Here are three reasons why:

1. Less sharing, more conversation

If you've built some part of your business on the ability to attract a wide audience through content on Facebook's News Feed, you should know that things are changing. You'll need to rethink how you build engagement and adapt your social strategies to be more focused on building communities and creating conversations.

For example, if you're a sporting goods store, you could create a group for local runners to share tips and ideas. You could host events like training runs will drive real-world engagement instead of simply chasing after likes and comments. And theoretically, you'd do it all through Facebook.

At the same time, remember that Facebook is--at its core--an advertising platform. De-emphasizing the News Feed will probably force you to pay more for advertising to stay in front of your target audience. You'll need to determine whether that extra money is worth the payoff.

2. Privacy is a huge concern

Facebook has made a public commitment to changing the way it handles your privacy. To date, though, it hasn't shown an ability to effectively monitor or control the way developers and advertisers use your information. Facebook still has to prove that it can be trusted to keep bad actors from running rampant with your data.

Interestingly, nothing in this update appears to change your ability as a user to control whether and how Facebook shares your information with developers and advertisers, or how it keeps our personal data secure. The business model is still the same: Facebook makes money off of knowing everything about who you are and letting advertisers target you with what it thinks are relevant ads.

On the plus side, Facebook has said that it now features end-to-end messaging encryption in all of its apps. I wouldn't hold my breath that it has actually solved the data privacy problem.

3. Mobile first

It's not an accident that the redesign is being released on Facebook's mobile apps first. Facebook makes over 90 percent of its advertising revenue from mobile users, and is clearly committed to increasing engagement among those users. Facebook's new apps for iOS and Android devices should start being available through software updates almost immediately, which means that the impact of the design shift won't take long to notice.

Facebook's strategy of facilitating personal communications is directly tied to mobile. This could be good for you, for both your personal and business accounts, provided Facebook actually figures out how to balance its interest in your data with the significant privacy concerns that still exist.

If that ever happens, Facebook could become more than just the place you go to share photos -- it'd be very useful as an actually secure messaging platform. In the meantime, this is another sign that you need to be deeply thinking about how you're reaching customers in an increasingly mobile-first world.

The browser interface redesign is expected to roll out in the coming months. The long-term impact of how this redesign will impact Facebook's business -- and the business of every organization that uses the platform -- is obviously hard to predict. More importantly, though, it's hard to overestimate.