On a global and multilingual standpoint, when doing SEO in multiple languages and cultures, only a native language SEO specialist would truly understand the behaviors, usage, and types of keywords that respond to their market. Outside of the implementation of hreflang and market/language rich keywords, all the same rules apply to multilingual SEO as in regular English SEO.
What's the authority of your website or webpage, or any other page on the internet for that matter where you're attempting to gain visibility? Authority is an important component of trust, and it relies heavily on quality links coming from websites that Google already trusts. Authority largely relates to the off-page optimization discipline of SEO that occurs away from the webpage as opposed to the on-page optimization that occurs directly on the webpage. http://youtu.be/0Y6hluMPulU