You are welcome. I've studied what makes a story be picked up. It's mostly time of the day and the name of the submitter. Here are my partial findings:

http://hnpickup.appspot.com/hnpickup_ratio_visual_analysis.p...

More to come. Probably, this week I will get around publishing something on the "karma growth effect".

BTW, I've sent an email to "help@leanpub.com" about latex math support. So far I haven't heard back.