The simple answer is: No. You don’t need to submit your site to any of the search engines, but there is no harm in doing so.
The reality is Google, Bing and Yahoo are really the only search engines that are going to bring you any considerable traffic. These major search engines, along with some of the minor ones like DuckDuckGo and ixQuick, are able to automatically find and crawl your site. So, eventually your site will get indexed without you having to do anything. There is one exception: If you have configured the robot.txt file to prevent the search engines from crawling your site.
As for all the smaller search engines out there, there is really no point in submitting your site to them because you will rarely see any traffic coming from them.
With that said, why would anyone want to submit their site using a search engine submission service? Again, there is no need to, but you might want to:
- If you have a brand new website, and you want to get it indexed faster.
- If you want to save time and submit your site to multiple search engines at once.
- If you want to submit your site to some of the lesser known search engines.
If you are using a free search engine submission service, then by all means go for it. There is no harm in using such services. If you are about to use a paid submission service, then stop and save your money. There is no reason to pay for a search engine submission.
Note: Do not get search engine submissions mixed up with directory submissions. They are not the same thing.