You have created website and You are applyting all techniques like SEO, Google Adwords, SMO, SMM, Email Marketing etc and you are getting good traffic to your website. but how will you monitor your traffic? How will you find that from where traffic is comming.
One Good solution is Google Analytics. with Google analytics You can Track your website visitors effectively. you can see your live audience data. You can check which advertising techniques are working for you etc.