Mobile is a big thing at Facebook now, with more than half of their users accessing the social network on its mobile app. And here's where its going to get messy. There'll be more Facebook Newsfeed ads coming at you soon.

In their earnings call, their primary focus was to convince advertisers that Facebook ads aren't a waste of money. And mobile has been a particularly tricky platform for them, and there wasn't a way to place ads on a 4 inch screen.

So now, it's turning to Sponsored Stories, which, is already generating $1 million a day for Facebook. On a mobile screen, they're basically a full-page ad. They're by far the most successful type of ad that Facebook has.

Thankfully, Facebook says it's being really damn careful about screwing with the newsfeed. COO Sheryl Sandberg said, "We've been fairly cautious about only rolling out a certain amount [of sponsored stories] and we intend to continue to be cautious."

Ads are going to be inevitable.