18. SEM : en.wikipedia.org/wiki/Search_engine_marketing SERP: http://en.wikipedia.org/wiki/Search_engine_results_page SEO : http://en.wikipedia.org/wiki/Search_engine_optimization PPC : http://en.wikipedia.org/wiki/Pay_per_click SEO vs PPC: http://www.mikesquarter.com/seo-vs-ppc-the-pros-and-cons-378/ SERP : http://en.wikipedia.org/wiki/Search_engine_results_page Adwords : https://adwords.google.com/support/aw/?hl=en Meta Data : http://searchenginewatch.com/2167931 Bounce Rate : http://en.wikipedia.org/wiki/Bounce_rate