Kai Ryssdal: I’m going to go out on a limb here and guess that most of you don’t have any idea how much data your smartphone eats up every month. For those of you with unlimited data plans, you don’t have to worry — yet.

But starting Sunday, new AT&T customers will be paying more. They’ll get more data, sure, but Marketplace’s Jennifer Collins reports the cost of being connected just keeps rising.

Jennifer Collins:  First, I’ve got to do the numbers. The average smartphone owner uses about 600 megabytes of data per month. That’s according to Nielsen. In video-speak, that’s roughly an hour on YouTube or 1,200 stops on the web or 3,000 emails.

AT&T’s cheapest plan gave users 20 minutes of straight video. It cost $15 a month. That’s not enough says tech analyst Jeff Kagan.

Jeff Kagan: Right now, many of their customers are getting burned. When customers get burned, they’re unhappy and when they’re unhappy they leave. That is what AT&T is trying to stop right now.

It’s trying by giving customers more data to watch baby pandas, piano playing cats and dog owners teasing their talking pets about bacon.

“Ultimate Dog Tease” video: So I ate it. Oh no. You’re kidding me.

Under the new plan, that cheapest tier will give users 30 minutes of straight video, and cost $20 a month. What’s our love of smartphones and tablets doing to our cost of living? Dan Ginsburg tracks inflation for the Bureau of Labor Statistics.

His index shows cell phone plans have gone down in price, but data charges?

Dan Ginsburg: Any extra prices for additional access, we’re not currently picking up.

In other words, it’s hidden inflation. AT&T says it needs to raise fees so it can boost its network to accommodate its users. But Jeff Kagan says even the new plans don’t offer enough.

Kagan: Because customers will be wanting more and asking for more and using more.

For now, though, the main carriers are only looking to increase the data cap.

I’m Jennifer Collins for Marketplace.