The first principle illuminating how people use the Web is that it takes value for a Website to be "sticky." A 1998 article in Science magazine stated that Web surfers are constantly making a judgment about continuing to visit a Website or exiting the site. Two factors come into play: the value of the current page and the promise of value in future site pages. That is, even if the current page has a low perceived value, if there is an indication that the quality of pages may improve, users will stay on the site for another page or two more. But if there is no value, they will leave the site very quickly. This is why we hear so often that "content is king." When they leave for lack of value, they are never coming back.
The second principle is that there must be a balance between the difficulty of using a Website and the rewards the user obtains from the Website. The term "flow" has been used to describe what occurs when a user loses himself in a Website. Flow occurs when the user becomes so absorbed that time and task temporarily become unimportant. Whatever the user started out to do online gets temporarily forgotten while they enjoy your site. When flow occurs, direction, inhibitions, and caution give way to impulse, and the user is much more likely to join or buy something promoted on the site. The site must be both interesting and easy to navigate for this to occur.
Flow is also a concept that applies to movement from one Website to another. Banners or textual links must be in context and create a smooth transition from one site to another to be effective. Otherwise, the flow is broken and interest is lost.
from George Little's Internet Income Course. Register to SFI for free and get immediate access to the complete 79-part course.