Getting listed in the top results for search terms of interest to your business can be one of the most important factors that determines the success of your internet marketing. A search engine marketing firm assists you with trying to get to the top of the free, or 'organic' listings on the major search engines.
Search engine marketing firms may use two different techniques. The first is called the 'black hat' technique, and focuses on tricking the search engine. The second is called 'white hat' technique which gives the search engine what they want to consider your site as the best result for a specific search term.
Black-hat approaches are risky and most reputable search-engine marketing firms avoid using them. Some of those approaches might even get your site permanently banned from major search engines, so you must make sure that the search engine marketing firm you retain doesn't use those techniques.
White hat techniques are varied and include both what is called 'on page optimization' and 'off page optimization.' On page factors have to do with the construction of your web pages to make sure that they are seen by the search engines as being relevant to the search terms of interest to you. Off page factors are where the bulk of the search engine marketing firms put their efforts.
The many off page techniques can be very confusing to a business owner who is not familiar with the details of internet marketing. Without confusing you with all the technical details, I can make it quite simple to understand. It really comes down to a search engine, such as Google, which will prosper or die depending on it's ability to provide useful results to the public user who wants to find information.
Search engines must select first page hits from numerous web pages from all over the web - how do they do it? When a website contains a link to a page on your site, this constitutes a vote. The more websites contain links to this one page (virtual votes), the higher its rank will be, as well as the rank of the pages that do the linking. You see, this way webmasters themselves get to vote on the relevance of each page. Nothing complicated here. It's important to realize that each page is ranked in its own right; not a complete website.
Search engine marketing firms help website owners and managers get their pages ranked as highly as possible on the major search engines. Their services range from consulting as you do the work, to doing all of the necessary work themselves. The price of these services vary from quite modest to very costly. Remember that you cannot improve a page's ranking once and keep that improvement forever. Keeping your page highly ranked is an ongoing endeavor, and will cost money on an ongoing basis.