I came across this little factbook from AdvertisingAge. It covers some interesting topics in the realm of Search Engine Marketing (SEM) and gives a taste of this phenomenon. Inside you’ll find stats galore, mini case studies on the top five search engines, and lists of the top search terms/keywords and top sites visited per category. I particularly liked the article on “Things to pay attention to in 2008″. For what its worth (a very brief overview of SEM), I encourage you to take a look.