Identify and compare the revenue model for Google, Amazon.com and eBay

Direct online sales model (Amazon.com)
You can establish your website as your place of business and directly sell to those entering your "store" to make a purchase. Since delivery is often by mail, this is similar to customers buying from a mail order catalog. Software products, e-books, music and video files can be delivered to the customer through the downloading process. Customers can browse through a variety of merchandise, mainly book titles and make comparison with other retailers to get the best online deal.

Online advertising space model (Google Adsense)
Just as television and radio stations gain revenue from advertisements, related to the reach or number of viewers they have, so too can popular websites charge for the number of viewers seeing an ad. A better method is to count the number of viewers that click on an ad, taking them to the company's website. This is increasingly popular due to its simple and easy implementation that can be added directly to one website or blog to increase its revenue.

Online commission model (eBay and PayPal )
Individuals and companies can also be established as affiliates, where they gain a commission for sales made through a company using the direct online sales model. For example, customers of eBay might need to create an eBay account to shop if they do not have a credit card. In addition, for customers that have a credit card but do not wish to use it for online transaction due to security issues will consider creating an eBay account to act as a medium for online transaction
purposes.

*Reference: Retrieved from www.school-for-champions.com/ecommerce/business_models.htm on 15 June 2009.