The Wall Street Journal expects Facebook revenues to break the $1 billion barrier this year, and the business news outfit estimates revenues of $1.2 billion to a stunning $2 billion.

Facebook has over 400 million users and is widely expected to file for an IPO this year, which will without a doubt make it the biggest tech IPO since Google.

Playdom, the social game company, has announced that they’ve acquired Facebook game developer Offbeat Creations. Playdom is more popular on the MySpace game market than on Facebook and is looking to expand more into the Facebook territory. Their most popular Facebook game, Mob Wards, has over 10 million monthly players. Playdom has raised $43 million in Venture Capital so far.

Perfect Market, a startup which helps online publishers get more revenue from their content, have announced that they’ve raised $6 million in a Series C funding round from the Tribute Company, the big news publisher behind LA Times and Chicago Tribune. Perfect Market has already raised over $15 million in their previous two rounds of funding.

After days of rumors, it’s been confirmed that online dating site Match.com has acquired Singlesnet for an undisclosed sum. Match.com says the acquisition is more a “value acquisition than a strategic one”, and assures that Singlesnet will continue to operate independently.

Last year, Match.com bought another competitor, People Media, for a cool $80 million. The Singlesnet deal is rumored to be half that.

Yelp has been hit with a class action lawsuit alleging that the online review service extorted people for money. The lawsuit has been brought by a veterinary hospital in California, which claimed they asked Yelp to remove a negative review, where after Yelp demanded $300 per month in fees to remove negative reviews.

The lawsuit alleges that Yelp runs an “extortion scheme” and has “unscrupulous sales practices” — Yelp has responded to the suit by saying they will “dispute it aggressively”.

Reply.com, a local advertising marketplace, has filed an IPO where the company plans to raise $60 million in capital in an initial public offering.

Reply.com offers a cost-per-click marketplace that’s heavily localized, in contrast to Google’s Adwords, among others. The company had revenues of $32.6 million in 2009, and profits of $2.5 million during the same year.

One of the most sought after, traded and talked about domains online is sex.com, which has been bough and sold several times over the past years, each time bringing in more money than previously.

Last time it was sold, the price was $14 million, but because of lack of payment from the purchaser, and general financial trouble, the domain is now up for sale again, and the bid starts at a cool $1 million.

The domain could very well break a record and sell for $15 million very soon.

Facebook has finally caved in to a lot of user requests to add the very popular PayPal as a payment option to its Facebook currency, which is used to buy virtual gifts, among other things. Also, you’ll be able to use PayPal to purchase Facebook ads, which we’re sure a lot of advertisers will appreciate.