Advertising on Social Networking Sites

After reading through the articles "Advertisers Face Hurdles on Social Networking Sites" and "Why Advertising is Failing on the Internet", it seems that there are a multitude of difficulties that advertisers face in the online world.  Members of social networks use them to keep up with their friends, not to keep up with brands.  This makes the ads be perceived as obtrusive to users and they ignore them.  This perception of ads can be projected onto the products being advertised and cause consumers to gravitate away from using those products.  When consumers are searching on Google, consumers are often in the mindset to make a purchase and the perception of the ad is not as negative on their platform.  Personally, it seems to me that Facebook has taken the approach of making ads more aggressive instead of more entertaining.  I think that eventually Facebook will find that the ads are detrimental to the user experience on Facebook and will eventually reduce their user base.