Joe Marren gives two universal keys to webwriting in his article Writing for the Web.

First key: know your audience.  Easy navigation and informative sites are important to readers. 

5 things you should have to attract the audience:

• have informative subheads
• good usage of bold text
• bullets
• short paragraphs
• pictures.

Second key: have an interactive site by having slideshows and surveys.  Suggestions on how to improve your online writing through the two key points include emphasis is on imagery and the ability to show the reader instead of telling them. 

It is important not to have long stretches of gray or black   Marren believes you should give the ending away early in your story.  The reader may just scan your article.

The why and how of a story are important online.