With Facebook's share price sinking dramatically after its initial public offering last month, many people have been making dire predictions about the future of the social network.
Michael Wolff wrote that, rather than being the new tech giant (the new social Google, if you like) Facebook was, in fact, one of the has-beens of the internet world – another Yahoo! or AOL in the making.
Putting such arguments aside, Facebook continues to represent great potential for marketers.
Yes, General Motors has said it is ditching advertising on the site, and others may well follow suit, but the real opportunity when it comes to Facebook will not be on the web, but on mobile devices.
It is almost certainly the future of the platform, but until now, we haven't known how exactly it was going to work.
The question has hung over the social network and should have been answered before the IPO, rather than telling investors that mobile was generating no 'meaningful revenue'.
Automated ad buying
Last week, Facebook took a huge step toward securing that mobile future as it began automating ad buying, making the process easier and faster, and opening up mobile advertising to more brands.
To date, mobile ads on Facebook have been available only to big advertisers as part of major ad packages.
Yet more than 60% of Facebook ads are bought by smallto medium-sized advertisers on a self-service basis.
Now, for the first time, they can insert Sponsored Stories in users' mobile timelines and access customers who had been off-limits.
It will allow marketers and agencies to target the gaps between things; and for marketers, gaps are the future.
These gaps (called 'interstices') are increasingly important to marketers. They are no longer empty spaces, as they were before the arrival of smartphones.
They are now filled with content and ads.
The time it takes to travel to a shopping centre or the local pub is now time we spend in the company of our smartphone and social network of choice.
By introducing targeted ads into a user's timeline in a quick and easy way, Facebook is creating opportunities for marketers.
Some brands will no longer need to advertise on Facebook itself, but can buy mobile-only ad campaigns. If you are a restaurant or bar, you need to find these gaps – and your customers.
Marketers need to overhaul their mobile strategies to ensure that they are ready to take advantage of the gaps in their customers' lives, rather than falling through them.
While many brands are already switched on to mobile marketing, the arrival of ads in Sponsored Stories could be a real game-changer for others.
It is something that brands will have to get on top of and start experimenting with immediately.
The changes will be a challenge for Facebook. Mobile ads promise much revenue, but the social network has to balance this with user experience, which it has always said is its priority, as it steps up the commercialisation of the platform. We will soon discover whether this remains the case.
Gordon MacMillan is social media editor at the Brand Republic Group and editor of The Wall blog @thewalluk. Follow him on Twitter: @gordonmacmillan.