27/11/2014
What Is Free SEO and What Is Paid SEM?
There are multiple definitions of what SEO and SEM are. In some cases they are even used as synonyms, which is not precise because they are very different, or SEO is included as a subcategory of the broader SEM umbrella, which is also somehow confusing.
Therefore, to avoid confusion, here is how we define SEO. SEO involves all the link building and onpage optimization activities the purpose of which is to achieve good rankings in organic search, while SEM is everything else you pay for, such as PPC traffic. You might ask if this means that paid links belong to SEM. No, they don't – they are simply black hat and they belong neither to SEO, nor to SEM.