Hello sir do search engine optimization for your website, try to increase daily visitors to your website create more backlinks for your website. i am sure your website will rankup. soon

The most important factor is time.

organic traffic means which comes to your website through unpaid services like from google, bing, yahoo and which is long lasting traffic, where as the inorganic traffic means which comes to your website paid services like PPC, Adsense which short period of time.

I would like to know about the sub domains and there benifits for us. Do Sub Domains really help us out for boosting our keywords?

Keyword density is very important from SEO point of view. The formula for Keyword density is No. of Keywords/ Total no. of word * 100. Keyword density must be 3% to 4% is good. If more than that google consider it as Key word stuffing. It is not good for website ranking.

Sitemap contains links of all the pages on our site. Sitemap helps google while searching any page. crawlers take information from stemap and show the results. So sitemap is very important for search engines point if view.

Doorway page is fake page that user will never see. It is for search engine spiders. They are come under black hat SEO.

The Google adword Keyword Tool being replaced by Keyword Planner. Keyword planner is also very good to find Keywords.

To rank in SERP page you have to work to get quality backlinks to your site. when you get many backlink your site will rank on SERP page. You can add fresh and unique content on you r site.

Google Adwords Keyword Tool is best tool for searching Keywords. There are many other tools like WordTracker, Keyword Discover etc.