A website gains high rankings through the quality and quantity of backlinks for it. Directory submission is a method through which such links are built. Unlike search engines, directories organize links under categories and sub-categories. The aspect of directory submission is important because it helps in the enhancement of inbound links to a website. Usually, search engines use web directories as strong referral system, because they can classify a set of websites in categories and rank them as per the value they provide.
When a website is included in a web directory there are high chances that it will be quickly indexed by the search engines. The crawler used by search engines to get results on a particular searched keyword obtains information on the recently updated or created links. These crawlers/spiders start the crawling with the web directories and first crawl all those links present in the directory. Moreover, whenever a search engine is launched, it usually obtains its results from the various internet directories to quickly index the already validated links.
Web directories do not expect a website to include their own links in exchange. This is beneficial as a website gets an inbound link without the effort of including an outbound link. In addition to the above mentioned advantages, a directory submission is usually an easy way to get associated with other website in the business field. So the process of directory submission in addition with other SEO services is beneficial for a newly launched site which is anticipating to be indexed soon or for an old site which is yet to be indexed by search engines.