Monitoring your site's stats

Are you always concern of monitoring your site's stats? Why? For me, it's valuable because we want to determine if our site's performance is good or not base on page impressions and unique visitors from different countries who are visiting our sites. SEO is really involved here, so we need to do whatever it takes just to maintain our site's traffic. But how can we determine the stats? If you're joining pay-per-click sites like Adsense, Smowtion, Chitika or Adzdaq, you will see your daily stats on the report page on how many clicks and impressions you receive. In terms of web optimization, your site's stats shall take in effect if optimized clearly and wisely. Right now, I monitor every single day of my blog's traffic to determine what's lacking for me and needs to improve. That's how important we should monitor our sites day by day, and SEO should be the one to take effect.