See these urls: http://www.google.com/search?hl=en&q=search+engine+marketing http://en.wikipedia.org/wiki/Search_engine_marketing
Hi, i think SEM is define as follows SEM = SEO + PPC SEO is narrow. SEM is broad. But SEO happens to be (currently) the most important aspect of SEM. for more you go here: for both seo & ppc http://www.brainpulse.com/articles/...sus-ppc-pay-per-click-advertising-part-1.html
SEM or Search Engine Marketing - the combination of SEO and paid promotions. SEO mainly focuses in free submissions and promotions.