Submitting site to search engine is profitable if you provide services that is available internationally or want visitors from all around the world. Search engines bring huge traffic to blogs/sites, it is no actually required to submit. There are sites based to local and only for specific community and same minded people where online game players can not benefit it. There are directories for niche sites you can find.
Classified sites for local search
For local search, people go for classified sites to put and get ads. There are many classified sites allow people to publish free ads some have limit and some require paid to renew but you will find almost all classified sites allow user to add free ads on their site. If you just want local customers to come to you then online classified sites are great idea to post.
Submitting your sites to search engine is free, no cost will apply. You can find services from SEO companies to send site URL to many search engines in one submission for this they charge as per services they offer.
Want to be found on major search engine
Do simple job, just submit your site to top search engine. If you have good related posts and keywords, people will find your site(SEO matter). If people type keywords and it is related to your site (description, keywords, words are marked by head tag, italic, bold) then your site will be in search result.
Some search engines are powered by google/yahoo/bing. These three are most popular and widely used, google search is in top no doubt. So if you add your site to google only that’s enough for small content/business.
Some search engine are based on directory search, search results are from open directory.
Submit content to google
Read WebCrawler submission guide