Every webmaster doing search engine optimization knows the importance of link building. Links are a measure of website popularity and are important for human visitors and especially for search engines. Most search engine algorithms use links and links parameters to calculate relevance of particular web page. Links are also an essential part of the PageRank algorithm used by Google. But it is not just the number of links that counts. There are few link parameters that should be taken into account when evaluating links and their value.
The first important parameter is anchor text. This is the text that actually links to your page. This text tells to everybody what your page is about. Anchor text is heavily used by search engines for additional clues about the content on your page. Therefore it makes sense to use meaningful and relevant anchor texts that describe the content on the target page. Usually the main keyword is used to create a relevant backlink to the target page. But you should never use only one word phrase to create links. Use various combination, let them look natural. Unfortunately, you don’t have control over what text will other webmasters use to create link to your site. But this is not so bad, you have a link and wide variety of anchor texts is welcome.
The second important parameter is the nofollow attribute. It marks links that should not be followed or taken into account by search engines. This means that such links are almost useless for SEO. The situation is not so bad because every link counts and even nofollow links are needed to make the backlink structure look natural. Of course, you should put more effort and time to get normal, do follow links, but never discard any opportunity to get a backlink regardless of its type.
The page where the link is located is also important. If the page content is related to the content of your page then the link is more relevant and has more value. The page relevance or authority (e.g. the PageRank value) plays also an important role in the link value. Links on high authority pages transfer the authority from the source page to the target page.
Link building services are a solution when you don’t have time or possibility to create links to your page, or when you have many websites that need off-page optimization. So the advantage of using such services is that they will create many links to your websites and if done properly you will be positioned higher in search results.
However, there are also some disadvantages in using link building services. You have no or little control over the off-page optimization process. If the links are created too fast or with similar anchor texts then some search engines will find this as unnatural and your site may be penalized with drop in ranking positions. Also the ratio between normal and nofollow links should not point to anything suspicious. With some services you may get many links from various link directories, but such links have little value. Such links are worth significantly less than links on pages with similar content.