Search Engine Marketing or SEM is a widely used term for a form of Internet marketing that utilizes an array of online marketing strategies to promote a website, improve its ranking on search engine results pages (SERPs), and increase its traffic and conversions. These strategies, inter alia, include search engine optimization (SEO), pay-per-click advertising (PPC), paid ad placements etc.

SEM predominantly (though not invariably) combines search engine optimization (SEO) which pulls in traffic (website visitors) from organic (natural) searches, and pay-per-click (PPC) advertising which helps to draw in qualified traffic (people who are already searching for the product category being promoted by the website) through sponsored ads (or sponsored links) put up by search engines (against payment per click) on the top and right-hand side of the SERP.

Combining SEO and PPC techniques in SEM helps to drive traffic to the website as they focus on different segments of potential visitors and have different types of strengths. SEO has strengths where PPC does not, and vice versa. PPC, for instance, generates traffic faster (sometimes in hours) than SEO (which may require 3 – 15 months) whereas the cost per visitor is much lower with SEO than with PPC. SEO helps to generate higher volume of low-conversion traffic (good for increasing site visibility) while PPC attracts more qualified (higher conversion potential) but lower-volume traffic and so on.

The trick to any successful SEM campaign is to optimize the site for both SEO and PPC separately and to have a judicious mix of the two strategies depending on the target market and the website goals.