The number of unique visits to your site - so the more people who visit your site, the higher the ranking
 The content of your site - this is so important. Write useful articles to share experience and knowledge of what you offer so that people return to read what you have to say. Become a useful reference site whose content s regyularly changing will increase your ranking
 The number of other sites that include a link to your site. This would seem to be relatively more significant to your ranking that the number of unique visits and site comtent combined. Spend time asking other companies who are in a similar generic business to yourself, to include a link to your web site and , in exchange, promise to incluse a reciprocal link ( sometimes called an "Inbound Link").
You may find it beneficial to employ the services of specialist companies to obtain inbound links for you. This can be expensive but once you have obtained a ranking that you want, you may not need to continue purchasing such services every month. Of course if your key phrase is highly competetive eg "Car Sales", then top reserve your position, you may have to budget a regular amount each month