Facebook made about $4.23 off your profile in the first three months of the year

• Facebook booked $4.23 in sales from each user worldwide in Q1 2017
• That's up from $3.32 a year ago, but down from $4.83 in the peak holiday season.

Mark Zuckerberg, chief executive officer and founder of Facebook

David Paul Morris | Bloomberg | Getty Images

Facebook's massive social network is free for users — but yet it makes billions of dollars in revenue every three months.

Indeed, the company reported $8.03 billion in sales in the first quarter of the year.

The company — which also includes Instagram, Messenger and WhatsApp — is the largest digital banner ad company. And over the first three months of this year, Facebook booked $4.23 in sales from each user worldwide, as overall ad revenue grew 51 percent from a year ago.

This time last year, Facebook made $3.32 per user. But the latest figure is down from the last three months of last year, when Facebook made $4.83 per user during the holiday shopping season, where advertising spend usually peaks.

"Seventy million businesses are now using Facebook pages around the world on a monthly basis, and more and more of them are becoming advertisers," chief operating officer Sheryl Sandberg said on a conference call with analysts on Wednesday night. "We also recently announced that over 5 million business are actively advertising on Facebook."

The ad revenue depends on the region.

As Sandberg put it, more businesses are seeing big impacts from the small screen, as advertisers think beyond television and print and look to reach consumers on their phones, where there is more information about their preferences.

Eighty-five percent of ad revenue for the first quarter was mobile, up from 82 percent a year ago, Facebook said on Wednesday.

Not only is Facebook drawing more ad money, but it is serving those ads to more users: The company added 80 million monthly users in the first few months of the year.