Then planning your web site, or even after it's up and running, it can be beneficial to explore other online revenue opportunities it could serve.

For example, there are 5 popular online revenue models.  These include (shown with examples):

Selling Products
Provide a web store where customers can purchase products by using credit cards, PayPal, or other payment methods.
http://www.amazon.com

Advertising
Google generates revenue primarily by delivering relevant, cost-effective online advertising.
http://www.google.com

Subscription Based Services
Users pay a monthly service fee to utilize the services available on the web site.
http://37signals.com/

Connection Services
Ebay makes money mostly by connecting sellers with buyers.
http://ebay.com

Lead Generation
Brochure type web sites offering information about the company to bring in new business.
http://www.TheOldState.com

Out of the 5 mentioned above, product sales are one of the most popular methods of producing revenue online.  Americans continue to spend more money than ever with online product purchases. The web continues to be the fastest-growing retail channel.  Selling physical goods can require warehousing, shipping, returns, and heavy customer service. Its a significant investment of time and/or money, but this has the highest revenue potential.

Advertising doesn't take much work, but you usually have to have a lot of traffic to generate anything substantial.  In order to generate the traffic, you need to make sure the content on your site is focused on topics which will attract a large audience.  People looking for the latest movie times don't usually click on ads.

Subscription and connection services can take some time to research, design, develop and test, and market to your target audience, but can provide great stability once the user base grows.

Lead generation is by far the most found type of web site.  Almost every company has at least something up on the web to build interest in the organization and explain who they are and what they do.

In some regards, it can be important to concentrate your web presence in more than one area of profit.  Many web sites utilize several of these online revenue models.  For example, Woly Board Company. Woly's web site delivers advertising (advertising space is seen on the pages), the ability to sell products online (eCommerce store), and lead generation (information and blog about the company).  

With this example, their company web site provides multiple uses for a single site and becomes tailored to several different users, focused on different areas.