If someone visits any page and leaves or quits without fulfillingone of these goals, the page has failed.
Each page is an advertisement, either for the information on the page, a function, info capture, or for information on another page. It has no other major purpose.
When your page works, people will complete one of the goals. Theywill continue to engage with the web site. When it fails, they’ll stop there and leave without getting what they want or giving what the page needs.
Any time you sit down to make a web page, ask, “What is the goal of this page? What is this page an advertisement for?”
And make it your sole goal to deliver that perfectly.