Facebook is launching a full-on assault at the nearly every major internet company, including Google, Amazon, Groupon, iTunes and Craigslist. The social network is leveraging its data on over 500 million users to create display ads like Google and Yahoo!, e-commerce like Amazon, FourSquare-esque local deals, apps like Apple and listings like Craigslist.

Although Facebook’s ad revenue reached a mere $1.86 billion in 2010, according to eMarkerter, we imagine the social network’s numerous alternative revenue streams to rake in much more cash and live-up to its $50 billion valuation. Here are just a few ways Facebook is diversifying its revenue streams and trying to take on the internet’s largest companies:

Ads — Facebook is taking a more psychographic approach to ad delivery than other big-time competitors like Google and Yahoo! / MSN — which could give it an upper-hand. In the first quarter of 2010, Facebook served up more display ads than any competitor (here’s lookin at you Google). During that time, the social network accounted for 16.2 percent of all display ads on the internet. In 2010 alone, Facebook served up 50 billion display ads per month and is on track to reach 1 trillion in 2011.

eCommerce — If Facebook’s Social Graph is any indicator of where the company envisions itself in the future, we should expect the social network to eventually become formidable foe of Paypal and Craigslist. Facebook Marketplace enables users to buy and sell goods, similar to Craigslist. And startups, like Moontoast,  are creating new apps for users and artists to buy and sell music, respectively.

Local Checkins / Deals — Watch out FourSquare, Facebook’s new FourSquare-esque Places feature enables users to find local deals as well. There are four types of deals: individual deals (for one person), friend deals (for two or more people), loyalty deals (for regulars) and charity deals (to donate to local organizations). Although Places hasn’t made as big of a splash as FourSquare, the social network has many many times more users than FourSquare and can scale much easier.

Apps — Target, Walmart and other national retailers offered Facebook credits in their brick-and-mortar stores this past holiday season. The online currency enables users to buy apps and virtual goods, such as grain in Zynga’s smash hit, Farmville. The revenue stream could begin to take off as the online gaming and social goods business is expected to increase to $6 billion by 2013 and Facebook’s 28 percent of the market is likely to grow as the social network continues to expand. If Facebook captures half of the market, it would bring in $1 billion — or half of its ad revenue — in annual profit.

Facebook’s revenue almost reached $2 billion in 2010, which was $3 billion behind than Yahoo!. However, that $3 billion gap is narrowing as Facebook leverages its massive database of user information to combine the business models of leading tech companies.