Be as truthful as possible - Do not lie to your readers, tell them the truth to the best of your abilities. If you don't know the answer, either tell them or find out the answer.
Fantastic idea - A subject that hasn't been covered over and over again, yet is something people want to know and read about.
Repeat viewers - People will come back again and again to re-read what you have written. To check something they might have missed the first time.
Share your Hub - At the bottom of every Hub, just above the comment section is not only the voting section, but also a 'share' button. Your Hub can be shared with readers on facebook, myspace, digg, blog, twitter etc...
I hope this helps to clarify your question.