If you want to viral your website by paid. You can go facebook. You can promote your website in facebook without fee. But this will not get so much visitor. Also if you want using Youtube. You can promote any website. But before promote or viral any website you need to done. Proper SEO for youtube. Without best SEO you can't get good result. If you want to viral your website in seo. You need to rank your youtube video first and share in social sites.
I'm using facebook page to promote my website :)
You should try youtube and maybe a special page on facebook if you want to get your site viral and to be more viral try a small domain ex abc.com instead of abcdefghijklmnopqrstuvwxyz.com because it's easyer to type and to remember.Try something unique to be at the top of google search, advertise it on a few forums and it should be viral in some weeks because if it's cool and usefull the people will recomend it to other people and so on.
I think that the best way to promote your content is through all the social network like Facebook, Twitter, Instagram , snapchat and Google+ for search indexes on google. It's very important to post continuosly, dayly content.
I own a public minecraft server so I prefer to use Facebook and Twitter, but I also use YouTube.
Add me on Discord Austin | SensualOrange#3553
If you wish to join me on my adventures as a minecraft player/pvper then add me on discord or send me a PM on the forums!