Finding my three quarters

So I sat down a day or two ago and worked out just how much money I make each month that is, give or take a few hours of maintenance, passive income.  It turns out I'm about one quarter of the way to my R20k a month goal.  That is, I make just over R5000 a month without putting in any "hard" hours.

Well, with that in mind (and on paper), I now needed to figure out how to get the remaining three quarters and, by golly, I think I've got it :D

Using something like The 30 Day Challenge, if I could set up 15 sites that each make a little over $100 p/m each, I'll be golden :)

Is it feasible to set up 15 good sites in the next 5 months?  If I put in the hours, sure!  Will each make $100 p/m from the geto-go?  Unlikely but some of them certainly will and that will put me in a stronger position than I am in now, so it's hardly a fail.

The biggest trick in getting this right will be doing the research part.  If I develop a coupla sites around dud-keywords, I'll be wasting time, so I need to spend enough time doing research so that, when the time comes to actually do some SERIOUS work, I'll have a much greater chance of actually making money instead of wasting precious hours in my day.

Another thing that comes to mind is the possibility of using these 15 sites to help boost the traffic to some of my other sites that are already making me some money.  Cross-pollinating, if you will.  That should definitely make the exercise worthwhile.

Will it work?  Well, let's see :D