Let’s try to put ourselves in shoes of search engines owners and creators. A few years ago, a directory submitting to thousands of other sites required a lot of work, time and determination. After the software and online scripts, which automatically submit pages to directories, appeared, gaining hundreds or thousands of links in a short period of time is not a problem any more. At the same time, the number of websites is growing every day and it increases competition for particular keywords. The search engines have to find sites which best suit to the search phrase from millions of sites.
Due to the above mentioned factors, the creators of search engines were forced to use special filters. In their opinion, on the one hand, the inflow of the large number of useless links from sites submitted to the thousands of directories is limited, and the focus is only on these which prove the real quality of the page. On the other hand, only these sites, which best suit the topic of the search, are fund. Therefore, nowadays it is better to have our one or two links on quality sites than one hundred in useless directories. At the same time, much attention should be paid to the optimization of keywords, which still is main factor of determining the theme of the site.