Facebook's (META -14.26%) attempt to appeal to small businesses certainly isn't new. But the social network has been going out of its way to make its platform a go-to mobile solution for this key target market lately. In a recent interview with The Wall Street Journal, COO Sheryl Sandberg explained why Facebook is becoming so crucial for small businesses. Here are key excerpts from the interview, along with some relevant background information.

Setting up a page and learning to use it is easy
Facebook has attracted 45 million small and medium-sized businesses so far. And this number is growing rapidly. In April, this figure was just 40 million. Going forward, it expects this number to continue to grow.

There's good reason for Facebook management's optimistic outlook for its social network as a platform for small businesses. Key to management's confidence that it will continue to attract small businesses in droves is the fact that it is so easy to set up an effective mobile presence on its platform:

If you can set up a Facebook profile, you can set up a page. You don't have to learn a new technology to do it. You don't have to learn a new system. ... [Conversely,] [m]obile apps are hard to develop and it's very hard to get your app downloaded. ... So as users' time and attention is shifting to the mobile screen, (Facebook) pages are the mobile presence for most of these small businesses. And there's nothing else out there that's this easy and this simple to use.

Furthermore, it's not only easy for businesses to set up a Facebook page but it's easy to use. A Facebook business page offers businesses an experience that is similar to the News Feed experience they are used to with their personal page, making it instantly familiar.

And Facebook wants to make operating a mobile business page even easier and more affective. As CEO Mark Zuckerberg explained during the company's second-quarter earnings call, the company is intently focusing on "delivering more useful tools and resources to help [businesses] achieve their goals." And "supporting small businesses," Zuckerberg said, has been one of its key focuses in this area.

Unparalleled reach on mobile
Facebook wants small businesses to build a mobile presence. And small businesses should want to, too. Why shouldn't they? Not only is it easy and fast to set up a presence on Facebook, but, as Sandberg explained to WSJ, the platform is "broadly used."

Facebook and Instagram [ -- a photo sharing service owned by Facebook --] get more than one in five minutes (that users spend) on mobile phones. So as users' time and attention is shifting to the mobile screen, (Facebook) pages are the mobile presence for most of these small businesses.

Or, measured in sheer numbers, consider this tidbit: About 1.31 billion mobile users check Facebook on a monthly basis and an impressive 844 million users connect to Facebook on mobile devices on a daily basis.

Managing a mobile Facebook page, therefore, is perhaps the most effective way for small businesses to get in front of users when they are on their mobile devices.

Recently, Facebook has been making it easier for businesses to communicate with customers through its Messenger service. It has also been prominently highlighting Messenger, encouraging business-to-customer interactions through the service. Image source: Facebook.

And make no mistake: People are on their mobile devices a lot -- and increasingly more so. Mobile media time per adult in the U.S. is now at 2.8 hours a day, on average, according to data from Kleiner Perkins Caufield Byers. This is up 11% from last year, and well over the average time on desktop of 2.4 hours a day, KPCB reports.

Noting that 35% of small businesses don't yet have a small business page, Sandberg acknowledged during the WSJ interview that there is a huge opportunity for Facebook to continue to attract more small businesses to its platform. And the social network will undoubtedly continue to take steps to attract them.

Investors should keep an eye out for a continued rollout of tools that make having a mobile presence on Facebook easy, effective, and pertinent.