One of the most important, if not the most, aspects of internet marketing is the SEO, or the search engine optimisation. Optimising a website in order to increase its popularity and the number of viewers includes few aspects. One possible way of website optimising is altering the content and the HTML in order to enhance the performance of the website, which will also contribute to its relevance. Another thing is to improve the indexing of the website and this can be done only by someone that understands how the search engine functions. If you don’t know how to do any of the SEO and you do own a website and you want to get better traffic for it, luckily for you, there are certain companies that offer SEO services on the market. Besides activities connected directly to your website, increasing its popularity by the use of links is another aspect of the SEO. These services are all united under the name link building services, since there is more than one way of increasing the website’s popularity. The aspect that they target is called website off SEO, because it is not directly connected to the website, but rather it has to do with other websites and social networks, such as Facebook, Twitter as well as blogs. Some companies offer blog commenting as a special link building service.