Search Engine Marketing is superset of SEO. In SEM, we also cover paid search results using tools like Google Adwords, Bing Ads, LinkedIn Ads and Facebook Ads. SEM also involves article submissions and Social Media Marketing (SMM)
Search Engine Marketing is typically a long term process that yields results in 3 to 6 months. Regular SEM helps in organic visibility of your website in search engine results.
If you ended on our website without any direct customer reference, our SEM works :-) and we can provide similar services for your website.