Facebook changed everything, but just like its debut toppled early social media giant Myspace, another social network will rise someday to knock Facebook from its mighty throne. And experts seem to think the next big thing in social media will debut on mobile.

Facebook has had many stumbles and missteps in its continuing journey to take over the world of social media, but its biggest problem has been its seeming incapability of adapting creatively to the mobile platform.

In pure numbers, it just makes sense: As of July 2012, 78% of 15 to 64-year-olds in the US now use a smartphone. People spend an average of 94 minutes each day on mobile apps as opposed to 72 minutes online through a desktop or mobile browser, according to Flurry Analytics. Just like the laptop replaced the desktop, the smartphone has become a user’s primary connection point.

Even more interesting, the usage of social media on mobile has a 60% increase year-over-year, and 20% use their mobile devices to access Facebook exclusively.

To remedy this, Facebook could simply buy-out smaller mobile platforms to strengthen itself in the mobile area. This is something that big companies like Google do all the time. Facebook purchased both Gowalla and Instagram over the past 12 months.

Facebook is still on top, and it could take a while before a challenger arises to topple its throne. But if there’s any point of weakness in the social media giant’s armor, it’s mobile.