http://getappcase.com/blog/app-stores/how-does-google-play-rank-mobile-apps

• 다운로드수 - including total number and also momentum; incentivised installs are still available in Google Play and can help in creating a snowball effect, or at least send you to the next download interval (100, 500, 1000 etc.), which improves visibility.
• 앱퀄리티 - 앱 다운후 실제 실행하는 비율과 수
• Frequency of interaction with the app - be honest, don’t build expectations that you can’t meet afterwards and don’t cater to the wrong audience.
• 설치후 삭제 수, 비율, 기간등
• 평점 및 코멘트 - these are important to how an app ranks, so any dev should make the most out of any reviews they receive and encourage more. Staying in contact with your audience and replying to reviews and feedback is therefore important to the app’s success.
• 국가?
• 키워드 비율 and relevance in the apps metadata
• Social ‘proof’ - meaning how many times the app gets +1s on G+ or Likes/Shares on Facebook and so on. 구글플레이에 몇번 +됬는지 페이스북에서 얼마나 좋아요를 얻고 공유되었는지;;;
• Number of backlinks - make sure you include links to as many relevant pages as possible. 백링크~