The three Cs of mobile - connection, convenience and context - and how they relate to online travel are increasingly hard to get away from.
They're often mentioned at travel conferences (more on the three C's, here) along with stats showing how mobile is a behaviour and not just a consumer technology.
So it was at the TTI Autumn conference in London earlier this week when Catherine Fitzgerald, travel lead for UK and Ireland, for the social networking giant, shared how Facebook views things and how mobile is now more than 80% of its advertising revenue.
To further demonstrate the mobile mentality she also talked about trends in media consumption "stacking not shifting" so that mobile means more time on digital media rather than less.
Then she moved on to apps highlighting figures from App Annie showing downloads for hotels and airlines.
Interesting to note the huge difference between hotel app downloads and airline app downloads with Ryanair coming top with seven million downloads in the past 52 weeks.
The carrier's Always Getting Better strategy is, it seems, continuing to reap benefits.
Then, when you add in online travel agents, the app download figures really begin to make you think - booking.com sits at the top with 32 million in the past year followed by TripAdvisor at just over 30 million.
But, look what happens when you add Uber - downloaded more than 116 million times in the past year.
Even if you think app downloads are a nonsense, the Uber figures at very least demonstrate the on-demand trend with the huge penetration and popularity of that particular service.
Fitzgerald also flashed up further support for how quickly things have changed in recent years.
Again, market capitalisation figures might not be everyone's cup of tea but look at how the likes of 'Digital Natives' such as Expedia, Ctrip and Priceline were valued in 2006 versus more traditional travel companies.
And, then look at them now with Uber, Airbnb and TripAdvisor also joining the list.
And, while online travel lines up its mobile ducks, it also has to grapple with new content formats - Fitzgerald says that by 2019 80% of content within news feeds will be video.
Then there's the rise and rise of messaging. Fitzgerald claims that Facebook founder Mark Zuckerberg wasn't that interested when the idea was initially touted via an in-house hackathon a few years ago.
Now it's a "one billion person a month app." And, of course Facebook also owns WhatsApp.
And messaging as a platform, not just Facebook's, is gaining traction with some companies now looking to add transactional capabilities so that all interaction with customers can be kept within one thread.
What does it all mean?
Kind of nothing but kind of everything because as Fitzgerald concludes with online "everything competes with everything."
Related reading:
Icelandair and Travelaer build airline industry's first Facebook Messenger booking bot
KLM confirms Facebook Messenger play