Facebook on Tuesday began letting marketing messages slip past ad-blocking software on desktop computers.

The update to the leading social network's advertising platform came with assurances that Facebook understands how annoying ads can be and with enhanced tools for controlling the kinds of ads shown to users.

"As we offer people more powerful controls, we'll also begin showing ads on Facebook desktop for people who currently use ad blocking software," vice president of ads and business platform Andrew Bosworth said in a blog post.

Ad blocking software typically does not work on mobile devices, which account for most visits to the social network, but are estimated to stymie billions of dollars worth of ads annually.

Advertising pays for online services that people have grown accustomed to accessing for free.

"Facebook is one of those free services, and ads support our mission of giving people the power to share and making the world more open and connected," Bosworth said.

Facebook ads on desktop are being made to look so much like natural content that they get by ad-blockers.

As a counter-balance, Facebook has made it easier to use its ad preferences tools that let people remove topics that don't interest them and stop advertising from businesses or organizations that have added them to customer lists.

"We've designed our ad formats, ad performance and controls to address the underlying reasons people have turned to ad blocking software," Bosworth said.

"People don't like to see ads that are irrelevant to them or that disrupt or break their experience."

In its latest quarterly report, Facebook said it took in $6.2 billion in advertising revenue, accounting for the overwhelming majority of its income. Some 84 percent of ad revenues came from messages delivered to mobile devices.