It’s day one of the Mobile World Congress, the big annual gathering of the mobile industry in Barcelona, and already the theme is clear: This is the year tech firms try to get the rest of the world online.

What does a $25 smartphone look like?

First, the basics: truly affordable smartphones. Mozilla, the makers of the popular Firefox browser and the forthcoming Firefox operating system for phones, this morning announced that it worked with partners to create designs that could be used in smartphone that costs as little as $25. Nokia released a touchscreen phone for €45 ($61).  A Chinese phone-maker was advertising a $35 Android phone.

Wow. We're on the cusp of connecting the entire world.

What the world ACTUALLY needs is cheap data plans.

But just because phones are cheap doesn’t mean people are going to rush out to buy them. A smartphone is an expensive proposition: owning an iPhone costs about $2,000 over two years in the United States: $500 for the phone and $1,500 for data, Facebook CEO Mark Zuckerberg said on stage at the conference today. Cheaper phones don’t necessarily come with cheaper data plans.

In India, for example, half of all smartphones owners don’t have a data plan, preferring to download things like video clips on the fly, and to use their devices for wi-fi. 

Mark Zuckerberg’s answer to all this is to provide a “dial tone for the internet”:

“Why should people spend one or two or three dollars to get basic data,” he said at the Mobile World Congress, if they don’t know what’s in store for them. People need a reason to get online and Zuckerberg’s idea is to provide a suite of free “basic services” such as messaging, food prices, Wikipedia, weather and, it goes without saying, Facebook.

This is the next step in Zuckerberg’s plan for world domination, which involves getting everybody in the world online and onto Facebook. He set up internet.org, a non-profit, to bring internet access to poor countries. And he introduced “Facebook zero” a light version of its service that can be accessed without incurring data charges with operators across the world.