The funny way Facebook praises the power of apps and predicts their irrelevancy

While Facebook's dreaming of an app-less future, it's also reminding developers to buy its mobile app install ads.

That was one of the funny contrasts at the first day of Facebook's F8 developers' conference in San Francisco on Tuesday.

During the keynote, the social media giant laid out its vision of the future, including a new platform to let businesses build "chatbots" to automate conversations through its app Messenger.

"This is the start of a new era," Messenger chief David Marcus told Wired, describing how he believes we're hurtling towards a future where messaging apps will become the hub for all of our activity, eliminating the need to download outside apps.

On stage, he built this case by describing how most people spend all their time in a small group of their favorite apps and hate installing new ones.

"We download fewer and fewer apps, and we certainly don't allow push notifications apps for new downloaded apps anymore," Marcus proclaimed.

The take-away: Developers should start building into Messenger to embrace the future.

But the tone was decidedly different during a later panel on driving growth with mobile app ads, where Facebook told app developers how great its ad products were for driving downloads and engagement.

Afterall, "87% of time spent on mobile is in apps," product manager Jehan Damji said on stage.

No reminders here about how most of that time is only spend in a select few apps (80% of mobile time is spent in a user's top three apps, according to ComScore).

Facebook's platform has driven 2 billion app installs and has 25,0000 active advertisers. It can charge significantly more for them than it can for other ad units, which made mobile install app ads one of Facebook's fastest-growing and most lucrative businesses.

Of course, Facebook is going to keep convincing businesses to use its services today while it tries to usher in the future. Facebook loves talking about its ten-year roadmap and it considers its big Messenger dreams a five-year project, not something that's ready now.

But it was a funny contrast attending both talks in the same day and seeing Facebook use the same auditorium to talk about the impending irrelevancy of apps and then, a few hours later, all the reasons why app developers should be plowing in money to promote their apps.