Facebook could boost revenue by as much as $800 million per year by adding Skype-like voice service, according to a report by the Copenhagen-based research firm Strand Consult. The question is, should it?

The report says Facebook’s sheer size could allow it to succeed where Google Voice and Microsoft, which acquired Skype for $8.5 billion in May 2011, have not. 

Facebook could, in fact be the "Skype killer," according to the Strand report. Facebook and Skype have a partnership, announced last year, to bring video calling to Facebook.

We've asked Facebook and Skype for their thoughts, and will update here when we hear back. 

Crucially, Facebook has payment-collection abilities that it uses for multiplayer games. It could use that function for billing voice-over-IP services. The report concludes that Facebook "could create a communication experience far richer than what is available today."

Jonathan Rick, who runs a Washington, D.C.-based social-media marketing firm The Jonathan Rick Group, noted that many inside North America have never used or even heard of voice over IP. That could work to Facebook’s advantage.

“Facebook wouldn't be competing against Skype and Google Voice, but introducing a brand new feature to its 1 billion users,” Rick said. “This makes for a beautiful opportunity. The risk isn't that people won't use VOIP; it's that they won't use Facebook's VOIP. In other words, the marketplace already exists; it's a question of whether Facebook can hack together the technology.”

Stefan Rust of business-app developer Exicon Global, however, cautioned that Facebook may not have an easy time taking on Skype. Skype is primarily used for business communication, whereas Facebook remains predominantly social.

“The beauty of Facebook (is that it) doesn't require active engagement and is ambient. It's a watercooler,” Rust said.

Facebook would be “much better off opening APIs to third-party VOIP providers to tap into their community that want to use VOIP. I have a Skype account and now want to communicate with someone on Voxer, and Facebook as a central hub would allow me to do that.”

The voice question comes as company observers say it needs to make a bold move to add revenue. The company’s share prices have slumped since its initial public offering in May and investors are getting restless.

“In this mindset, and especially with its stock down 50 percent, Facebook doesn't need to overtake Skype; it just needs to add another revenue stream,” Rick said.

“Despite Facebook's flock of failures -- ranging from Beacon to Offers to Places -- none of these has really hurt the social network's growth or reputation. Instead, taking a crack at VOIP squares nicely with Facebook's motto to ‘move fast and break things.’"