Hi Guys. All of you know that How a Search Engine Works. Cralwers always tries to find a new website. Every days crawling process is dont thosuands of times and it will strive for new data in the workd. So no need of submitting or adding your site to Google or any other search engine. But you have viral and trending content, if you wont submit URL to Google or other search engine User may miss your content as we dont no when crawler will come to your website.
What i am trying to say is Crawler will come to your website but we dont know when it will come. For that reason it is must that you have to submit URL to Google Search Engine
How to Submit-Add URL to Google
Visit Google and type Webmaster tools in bad. Thease days we are calling it as Search Console too.