People often ask, what is the difference between Search Engine Marketing (SEM) and Search Engine Optimization (SEO)? Well SEM is all about promoting websites to increase their visibility in search engine results pages (SERPS). That said, so is SEO.
The main difference is that SEM takes SEO a step further and includes looking at pay per click and paid inclusion as well as optimization. SEM is designed for those wanting a result immediately as opposed to waiting for the search engines to take note of the work done by the SEO.
Both SEO and SEM are forms of Internet Marketing, while both look at keywords, SEM also looks at other forms of online advertising; generally the costs are higher than a standard optimization service.
Drabdesign offers both SEO and SEM services to their clients, as to the costs, well that is niche specific. Each niche is different and often the more competetive ones are the ones that cost the most to optimize.