All I can say is because this particular journey is 100% WHITEHAT, there is so much more grunt work involved. You have to do promotion, you have to interact with forums that can help with sales, and you have to deal with issues no one likes to discuss. You have leaders in niches that hate competition, and will send their minions to rate down your books and leave neg feedback in an effort to stay above you.
There are so many more variables I could not ever have imagined when I first started. This journey is not over for me but I can tell you honestly it's consuming my days more than I thought. 16 hours a day last week to just tread water, because of all the little things you MUST do in order to start making serious money. I'm dealing with feedback bombing, bans from groups, and other BS that are just part of the game I guess. No one wants to willingly give up their top spots in each niche, and when they see newbies climbing up they bring out the Black Hat techniques to cut us at the knees.
I'm fighting the good fight and will post when I can after I take over the top spot in a few niches.