Ashot Jan, nothing is free but I will explain to you the basics of Search Engine Optimization.
Here is a scenario: owner of a auto leasing company located in Glendale has a Website up and running but hardly ever gets relevant visitors--meaning to say most of this traffic is worthless and thus what he thought was going to be an asset becomes a liability. Now, to increase relevant traffic he starts purchasing ads from the following venues: yellowpages, armenianpages, google adwords, yahoo pay per click, and so on, unnecessary money spent on media. Had he done an on-page optimization of his website to be geographically relevant he would not be paying loads of money to these ad agencies. SEO is based on many factors has many dependencies but the major categories are: Relevancy, Keyword Research, Age, Clean Code and Link Building. Each category has it's own set of costs but the most expensive one is the Link Building.
Now people searching on google the following keyword: auto leasing Glendale California will never get to his site organically. SEO is the solution for this scenario, you pay one time fee to get your on-page optimization based on relevancy and with in few weeks you start getting visitors who are actually looking for your business in the area you are physically located.
The dangerous part is when your competitors are doing this and you have not done anything to compete with them on the same search term.
Think about it and let me know your thoughts.
WS