this a MUST READ article :

"Dennis Yu, the CEO of BlitzLocal, a privately held 50 person advertising agency in Denver, Colorado, specializing in local search engine marketing for franchises and professional service firms via Google and Facebook. BlitzLocal is no longer in the business of spam, but they do specialize in Facebook advertising and are now using the platform they’ve developed to run campaigns for big brands and small businesses. Dennis writes a blog at dennis-yu.com

Did you know how Mark Zuckerberg supported Facebook in the early days, before he got venture funding? Casino ads. And how about those advertisers who were making over $100,000 a day selling Acai Berry and other weight loss products – they are friends of mine, pioneers of new advertising channels. You see those ads saying “Inbox (5). Nick, someone in San Francisco has a crush on you!” (with your name, profile picture, and city in the ad). I generated millions of dollars from these offers on Facebook – I am not proud of it, but it was very lucrative.

I will walk you through how these online scams work on Facebook and other social networks – the mechanics of how the money is made, some of the people involved, and who is actually clicking on ads. If you’re reading this article, there is a good chance that you are not the type of person actually clicking on these spam ads, but are you curious as to who actually is?

Source: http://www.techcrunch.com/2009/11/01/how-to-spam-facebook-like-a-pro-an-insiders-confession/

an interesting conversation in SlashDot also check it out http://games.slashdot.org/story/09/11/01/1421253/Scams-and-Social-Gaming?from=rss