We’ve been aware for some time that Facebook ads can be a great way to effectively get in front of your target audience. You can set it up brilliantly so that it only shows in front of exactly the people you want it to.

Apparently, the rest of the world is becoming aware too. eMarketer says that in 2011, U.S. marketers will spend about $3.08 billion on social networking sites. That would be a 55% increase over the $1.99 billion (that’s it?) that was spent in 2010.

And of course the majority of this is on Facebook. eMarketer predicts that $2.19 billion will be spent just on Facebook in the United States this year. And they expect it to reach $4 billion worldwide.

We are starting to think that this whole “internet” thing might be here to stay.