https://mixpanel.com/ja/blog/pmf%E3%81%A8%E3%81%AF-%E3%82%B9%E3%82%BF%E3%83%BC%E3%83%88%E3%82%A2%E3%83%83%E3%83%97%E3%81%8C%E8%A6%8B%E3%82%8B%E3%81%B9%E3%81%8D%E6%8C%87%E6%A8%99%E3%82%92%E7%B4%B9%E4%BB%8B/