Traffic from search engine is very poor?

Traffic from search engine is very poor?

My website traffic is quite pleasant however the contribution from search engine is very poor. Though I have manually submitted my website URL to all major search engines but the traffic is still very poor. I do not understand what is wrong and how I can increase traffic from search engines. In comparison to my competitors websites contribution of search engine’s traffic is very low. The total percentage of traffic from Google is just 15% of total traffic whereas contribution of Yahoo, Bing and MSN and other search engine is only 20% of total traffic.
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Digital Marketing Agency|SEO UK