Can you guarantee that? Because if you can then I think your question is moot.
If your reader has a vested interest in your content they will read it in its entirety. That is provided:
1) They have enough time right at that moment
2) The text is concise
3) It answers the reader's question, meets the reader's immediate need.
Another thing to consider is that people still print out online text. So provide an easy means of sending your text to a printer. This could either be a "print this" link or a link to export the file as a pdf document.
Finally you could foster the "viral" spreading of your content by making it easy for me to email it to others, provided that it meets a need that many people might have.