I can openly say that the more time I spend on writing any Hub the more successful the Hub becomes. There is a positive correlation between the amount of the time you spend writing the Hub and the success of that Hub as measured by traffic and earning. My highest earning Hub receives a traffic of 200-500 per day and it is ranked in the first place(position one for that long tail keyword) in Google.
When I was writing this hub I spend more than 5 hours on it .
I began with a very comprehensive Keyword Research, I analyzed the Keyword, took the related Keywords and made them Tags for the Hub, wrote a good summary and then submitted the URL to Google.
What am I saying here: The success of a Hub Depends with the Time you spend on it. I am willing to give a detailed account to anyone who would wish to know more about this.
Thank you and I hope this helps someone