Both online and offline marketing (such as email, blogging, direct mail, ads, etc) should all contain some sort of action item. In most cases, the action item will direct people to a website or landing page where they can learn more about a particular product, service, or promotion. This is very common practice and many of those channels can be utilized affordably. But this is where marketers often fail (or get hosed for that matter).
Take a short time to look at the diagram below. Each spoke represents some sort of marketing channel, or in my terms, a Website Chauffeur. These mechanisms capture the attention of their viewers and then chauffeur them to the website where the next step in the selling process begins.

Online chauffeurs are shown in blue and offline chauffeurs are shown in orange.
Website Chauffeurs are great at capturing attention and bringing individuals to the next step at the center of the spokes - the website (or the hub). But the problem is Website Chauffeurs don't convert visitors into customers. That is the job of your website. Wherever visitors land within your website your message should build value before attempting to make a sale.
This is why it is so important to have a simple and powerful Web content management system to help you adjust your message. Chances are you will not get that message quite right the first time, or the second time, or the third, fourth, fifth, or sixth time. Hopefully, you get the point. Having a tool that doesn't punish you for making changes is a necessity, unless you like to send cash to a developer at $100 per hour. A Web content management system gives you the capability to adjust the message yourself and save enormous amounts of time and money.