Do you think what is most important to SEO, keywords, backlinks or others?

I think in the first place you must have a content ...
Then, based on research, conceptualize content around the main key words or phrases ... Then build quality backlinks, and promote the site ...

ps:
The most important thing is to have the content that provide to the visitor becomes a client, and the essence of SEO is to help to bring more visitors to be able to get acquainted with your service ...

 

Yes.. I agree with you...convert your visitor into client is the best way....maybe you can put autoresponder script to your website in order to grab their e-mail for future marketing....