Facebook launched a next-generation online messaging service that includes facebook.com email addresses in a move seen as a shot across the bow of Google, Yahoo! and Microsoft.
Facebook founder Mark Zuckerberg on Monday unveiled what he called a "convergent" modern messaging system that "handles messages seamlessly across all the ways you want to communicate" in a single inbox.
The messaging service blends online chat, text messages and other real-time conversation tools with traditional email, which Zuckerberg said had lost favor for being too slow for young Internet users.
"It is true that people will be able to have facebook.com email addresses, but this is not email," Zuckerberg said at an event in downtown San Francisco. "It handles email."
Zuckerberg dismissed reports referring to the messaging system as a "Gmail killer" aimed at the heart of free Web-based email services from Google and similar services from Yahoo! and Microsoft.
"We don't expect anyone to wake up tomorrow and say "˜I'm going to shut down my Yahoo! Mail or Gmail account,'" Zuckerberg said.
But, he added: "Maybe one day six months, a year, two years out people will start to say this is how the future should work.
"Maybe email won't be as important a part as it was before and we can push people toward real-time conversations."
The new messaging system, referred to inside the Palo Alto, California-based firm as "Titan," will be slowly rolled out in coming months to users.
Approximately 350 million of Facebook's more than 500 million members fire off messages at the service, with more than four billion digital missives sent daily, according to Zuckerberg.
With such a large user base, a free personalized facebook.com email service is seen as a challenge to the established email giants -- Microsoft's Hotmail, Yahoo! Mail and Google's Gmail.
Hotmail currently has the most users, 361.7 million as of September, according to online tracking firm comScore, followed by Yahoo! with 273.1 million and Gmail with 193.3 million.
Microsoft, which has a small stake in Facebook, is integrating its popular Office software into the social network's messaging system so people will be able to share Word, Excel and PowerPoint documents as attachments.
Facebook's new messaging service comes amid sparring with Google over data sharing. Google this month blocked Facebook from importing Gmail contact information over the social network's refusal to share data about its users.
"Facebook says this isn't a "˜Gmail killer,' but this is neither completely accurate nor completely wrong," said Forrester analyst Augie Ray. "Anything that makes communication easier and pulls attention away from Gmail is a "˜Gmail killer.'"
"It will increase the amount of time people spend on Facebook," said Lou Kerner of Wedbush Securities. "That's really what a lot of this battle between Facebook and Google is about.
"All these Web companies want to have people spend more time with them so they can serve them more ads," he said. "So if people are using Gmail less and Facebook messages more that's to the detriment of Google."
Facebook users can decide whether to get word to friends using SMS, chat, email or a messages feature at the social networking service. Messages will be received in whatever medium or on whichever device is convenient.
"You shouldn't have to remember who prefers IM over email or worry about which technology to use," said Facebook engineer Joel Seligstein. "Simply choose their name and type a message."
Incoming messages are sorted into one of three folders. A main folder holds messages from Facebook friends, while bank statements and other worthwhile messages not from close friends go into a second folder.
Messages people don't want to see go into a junk folder.
One of the major objectives was to streamline sending and receiving messages with an eye toward simulating an ongoing chat, according to Zuckerberg.
Zuckerberg also said Facebook employees, who have been using facebook.com email addresses for some time, were transitioning to fb.com addresses after obtaining the rights from the American Farm Bureau.