When you use a content management system to track your ad/coupon effectiveness, you won't be left guessing.
When stored and tracked through the use of a database, who your online clientele are, and where they found you will be very obvious.
You will know exactly where your marketing efforts are working and where they are not.
Its a known fact that website visitors usually visit a minimum of three times before they purchase.
Through the use of tracking and statistics you will find out whether you need to change your online sales approach through this method also.
If most of the users show up once and never come back, its a strong signal that you need to change your sales copy online.
While you are doing testing, you will gather a list of your users, which can be used to generate more highly targeted e-mail and/or direct mail campaigns for follow up sales.