A website is no better than the visiting card you give out without SEO. If Google is not indexing your site properly, the domain might not even appear in search results. The right setup can go a long way.
SEM is the fastest method to put your website on the search engine front page. Google Adwords is a popular tool for advertisers to create ads on Google search pages and advertising network.
The greatest advantage in using SMM is it being potentially viral. It offers a direct channel for you to expose your products to target groups and have them speak your brand in the online world.